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Thibault, P. "Exercice infirmier : place de la formation douleur." Douleur et Analgésie 34, no. 4 (December 2021): 225–28. http://dx.doi.org/10.3166/dea-2021-0181.
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La formation des professionnels de santé, en particulier médecins et infirmiers, est un point crucial pour l’amélioration de la prise en charge des patients, de la prévention de la douleur aiguë au suivi des patients douloureux chroniques. Cet article a pour objectif de faire le point sur l’état des lieux de la formation, en particulier pour les infirmiers et aides-soignants, et de faire des propositions tant dans le domaine de la formation initiale et continue des professionnels infirmiers que dans celui de la formalisation de la formation des infirmiers ressource douleur, professionnels experts dans le champ de la douleur, dont l’expertise n’est à ce jour pas reconnue.
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Dikenstein, Violeta. "Vecinos en alerta: un rol difícil de institucionalizar. Estudio en la Ciudad de Buenos Aires." URVIO. Revista Latinoamericana de Estudios de Seguridad, no. 24 (May 10, 2019): 151–66. http://dx.doi.org/10.17141/urvio.24.2019.3790.
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En este artículo nos proponemos analizar la actividad de un conjunto de actores, residentes de un barrio del sur de la ciudad de Buenos Aires, que hacen de la inseguridad su ámbito de intervención, de ejercicio y de “trabajo”, a quienes denominamos –provisoriamente– vecinos en alerta. Desde una perspectiva cualitativa basada en la realización de entrevistas en profundidad con los actores implicados en el proceso estudiado y observación participante en los múltiples escenarios por donde circulan, reconstruimos los perfiles de los vecinos en alerta, el repertorio de actividades que llevan adelante, las relaciones que establecen entre sí y con otros actores, los lazos de coordinación y conflicto que entablan en este transcurso, así como las situaciones de interacción en las que este rol entra en juego. Hallamos que hay un repertorio compartido de actividades que desempeñan estos actores, variado dentro de ciertos límites. También, que el rol de vecino en alerta está sujeto a una constante negociación y redefinición, en las instancias de encuentro con diversas autoridades institucionales encargadas de la seguridad.
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In this article we propose to analyze the activity of a group of people, residents of a neighborhood in the south of the city of Buenos Aires, who make insecurity their area of intervention, exercise and "work", whom we call alert neighbors. From a qualitative perspective based on in-depth interviews with those involved in the process studied, and participatory observation in the scenarios where they circulate, we describe the profiles of the alert neighbors, the repertoire of activities that they carry out, the relationships they establish among themselves and with other actors, the bonds of coordination and conflict that they establish in this course, as well as the situations of interaction in which this role comes into play. We find that there is a shared repertoire of activities performed by these actors, varied within certain limits. Also, that the role of alert neighbor is subject to constant negotiation and redefinition, in the instances of meeting with various institutional authorities in charge of security.
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Lampert, Evan. "Use of U.S. Census Bureau Data to Expose Students to Dynamic Population Growth." American Biology Teacher 79, no. 7 (September 1, 2017): 572–77. http://dx.doi.org/10.1525/abt.2017.79.7.572.
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Global human population size and understanding how it has changed and will change in the future are important concepts for students. Here I describe exercises that use online databases provided by the U.S. Census Bureau to show students how both population size and the rate of change vary over time. In the first exercise, the U.S. population clock is used to calculate daily birth, death, and migrant and death rates, and how the world population clock is used to calculate the rate of change. These rates can be used to predict what the population size would be if the rates remained unchanged for a predetermined time interval. In the second exercise, historical data are used to determine the years with the most change in U.S. and world population size, then calculate how much larger the current population would be if those historical rates of change remained constant. These exercises have improved quantitative literacy while showing students current and historical trends in human population.
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Puech, Alain, and Bibiana Quiterio-Mendoza. "Caractérisation des massifs rocheux pour le dimensionnement de pieux forés en mer." Revue Française de Géotechnique, no. 158 (2019): 5. http://dx.doi.org/10.1051/geotech/2019011.
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Les pieux forés et cimentés sont une solution envisagée comme fondations de structures marines dans les roches tendres à dures rencontrées au large des côtes françaises. Le dimensionnement des pieux au rocher est un exercice délicat. L’exécution de séries d’essais de cisaillement d’interface à rigidité constante (dits essais CNS) est considérée comme une approche réaliste pour estimer la résistance au cisaillement de l’interface roche-ciment sous chargements statiques et cycliques. Les essais CNS sont conditionnés par deux paramètres clés qui sont liés aux caractéristiques du massif rocheux : la rigidité du massif et la géométrie de l’interface roche-ciment. Cet article propose une approche méthodologique pour estimer ces paramètres.
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A.F. "Charge virale de malales atteints du syndrome d'immunodéfience aquise (sida) et exercice." Science & Sports 14, no. 6 (November 1999): 305. http://dx.doi.org/10.1016/s0765-1597(00)86525-9.
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O'Connor, Sinéad, Paul McLoughlin, Charles G. Gallagher, and Helen R. Harty. "Ventilatory response to incremental and constant-workload exercise in the presence of a thoracic restriction." Journal of Applied Physiology 89, no. 6 (December 1, 2000): 2179–86. http://dx.doi.org/10.1152/jappl.2000.89.6.2179.
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In the presence of an externally applied thoracic restriction, conflicting ventilatory responses to exercise have been reported, which could be accounted for by differences in exercise protocol. Seven male subjects performed two incremental and two constant-workload ergometer tests either unrestricted or in the presence of an inelastic corset. Ventilatory variables and arterial estimates of Pco 2 were obtained breath by breath. Subjects hyperventilated in the presence of restriction during the constant-workload test (38.4 ± 3.0 vs. 32.8 ± 3.0 l/min for the average of the last 3 min of exercise, P < 0.05), whereas, at an equivalent workload during the incremental test, ventilation was similar to unrestricted values (unrestricted = 26.3 ± 1.6 vs. restricted = 27.9 ± 2.3 l/min, P = 0.36). We used a first-order linear model to describe the effects of change in workload on minute ventilation (24). When the time constants and minute ventilation values measured during unrestricted and restricted constant-workload exercise were used to predict the ventilatory response to the respective incremental exercise tests, no significant difference was observed. This suggests that hyperventilation is not seen in the restricted incremental test because the temporal dynamics of the ventilatory response are altered.
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Hourcade, J. C., G. Saulière, P. Noirez, J. F. Toussaint, and F. D. Desgorces. "Quatre mois de charge d’entraînement globale et par exercice chez le footballeur professionnel." Science & Sports 32, no. 4 (September 2017): 221–28. http://dx.doi.org/10.1016/j.scispo.2017.03.004.
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Martin, Jean-René. "7/10 Délégation de prise en charge en secteur libéral ou exercice regroupé." Soins 60, no. 798 (September 2015): 59–60. http://dx.doi.org/10.1016/j.soin.2015.08.014.
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Garnier, Yoann, Romuald Lepers, Hervé Assadi, and Christos Paizis. "Cardiorespiratory Changes During Prolonged Downhill Versus Uphill Treadmill Exercise." International Journal of Sports Medicine 41, no. 02 (December 2, 2019): 69–74. http://dx.doi.org/10.1055/a-1015-0333.
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AbstractOxygen uptake (V̇O2), heart rate (HR), energy cost (EC) and oxygen pulse are lower during downhill compared to level or uphill locomotion. However, a change in oxygen pulse and EC during prolonged grade exercise is not well documented. This study investigated changes in cardiorespiratory responses and EC during 45-min grade exercises. Nine male healthy volunteers randomly ran at 75% HR reserve during 45-min exercise in a level (+1%), uphill (+15%) or downhill (−15%) condition. V̇O2 , minute ventilation (V̇E ) and end-tidal carbon dioxide (PetCO2) were recorded continuously with 5-min averaging between the 10th and 15th min (T1) and 40th and 45th min (T2). For a similar HR (157±3 bpm), V̇O2 , V̇E , and PetCO2 were lower during downhill compared to level and uphill conditions (p<0.01). V̇O2 and V̇E decreased similarly from T1 to T2 for all conditions (all p<0.01), while PetCO2 decreased only for the downhill condition (p<0.001). Uphill exercise required greater EC compared to level and downhill exercises. EC decreased only during the uphill condition between T1 and T2 (p<0.01). The lowest V̇O2 and EC during downhill exercise compared to uphill and level exercises suggests the involvement of passive elastic structures in force production during downhill. The lower cardiorespiratory response and the reduction in PetCO2 during downhill running exercise, while EC remained constant, suggests an overdrive ventilation pattern likely due to a greater stimulation of efferent neural factors.
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Fortier, J., V. Julliand, P. Harris, and A. G. Goachet. "Training management of Standardbred trotters: a field survey in France." Comparative Exercise Physiology 10, no. 1 (January 1, 2014): 63–71. http://dx.doi.org/10.3920/cep13035.
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This study aimed to characterise the training practices of French trainers and to describe the training load undertaken by unqualified (UT) and qualified Standardbred trotters (QT). During the Paris-Vincennes 2012 meeting, 20 trainers from the Grosbois training centre were surveyed. Details of their general training practices as well as the weekly workloads for UT and QT were obtained. A nonparametric Mann-Whitney test was used to compare the UT and QT data and a principal component analysis (PCA) was carried out to examine links between trainer characteristics and particular training practices. Four main exercises used to train trotters were identified: (1) ‘promenade’ exercise: light exercise at walk and at slow trot (5.1±0.4 m/s) lasting 48±9 min; (2) ‘jogging’: moderate trot exercise (6.9±1.5 m/s) lasting 44±12 min; (3) ‘parcours’ exercise: moderate/high intensity trot session (10.3±0.9 m/s) over 2,844±1,412 meters with a final sprint; (4) ‘interval’ type exercise: fast trot sessions (10.8±0.9 m/s) over 1,010±212 meters with sprint phases. Trainers used a combination of these four exercises to train both UT and QT. Moreover, the estimated training weekly workload did not appear to differ between the two age categories, with apparently similar exercises and training loads being used to train both UT and QT. The results of the PCA suggested that as trainers become older and more successful they tend to change the composition of exercises used. They preferably used more ‘jogging’ type exercise, regardless of the horses’ age or training level. Whilst the weekly training plan varied between trainers, it seems that the individual trainer's annual programme was relatively constant, consisting of a repetition of a typical training week.
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Millar, Paul, and Anne H. Gauthier. "What Were They Thinking? The Development of Child Support Guidelines in Canada." Canadian journal of law and society 17, no. 1 (April 2002): 139–62. http://dx.doi.org/10.1017/s0829320100007031.
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RésuméAu début des années 1990, le Canada a débuté un exercice destiné à accroître les montants des pensions alimentaires pour enfants – pensions qui sont payées par le parent n'ayant pas la charge des enfants – afin de réduire les taux de pauvreté chez les enfants. En 1997, après plusieurs années d'étude et de coordination entre les gouvernements fédéral, provinciaux et territoriaux, le Parlement a adopté les lignes directrices qui lient les montants des pensions alimentaires au revenu du parent n'ayant pas la charge des enfants. Ce papier examine le développement historique des lignes directrices, et les hypothèses qui sont à leur base. Les buts initiaux des lignes directrices sont comparés aux résultats obtenus de façon à fournir des directions pour de prochains ajustements et réforme politique.
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Stenling, Andreas, Andreas Ivarsson, and Magnus Lindwall. "The only constant is change: analysing and understanding change in sport and exercise psychology research." International Review of Sport and Exercise Psychology 10, no. 1 (September 4, 2016): 230–51. http://dx.doi.org/10.1080/1750984x.2016.1216150.
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Gonzalo-Skok, Oliver, Julio Tous-Fajardo, Carlos Valero-Campo, César Berzosa, Ana Vanessa Bataller, José Luis Arjol-Serrano, Gerard Moras, and Alberto Mendez-Villanueva. "Eccentric-Overload Training in Team-Sport Functional Performance: Constant Bilateral Vertical Versus Variable Unilateral Multidirectional Movements." International Journal of Sports Physiology and Performance 12, no. 7 (August 2017): 951–58. http://dx.doi.org/10.1123/ijspp.2016-0251.
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Purpose:To analyze the effects of 2 different eccentric-overload training (EOT) programs, using a rotational conical pulley, on functional performance in team-sport players. A traditional movement paradigm (ie, squat) including several sets of 1 bilateral and vertical movement was compared with a novel paradigm including a different exercise in each set of unilateral and multi-directional movements.Methods:Forty-eight amateur or semiprofessional team-sport players were randomly assigned to an EOT program including either the same bilateral vertical (CBV, n = 24) movement (squat) or different unilateral multidirectional (VUMD, n = 24) movements. Training programs consisted of 6 sets of 1 exercise (CBV) or 1 set of 6 exercises (VUMD) × 6–10 repetitions with 3 min of passive recovery between sets and exercises, biweekly for 8 wk. Functional-performance assessment included several change-of-direction (COD) tests, a 25-m linear-sprint test, unilateral multidirectional jumping tests (ie, lateral, horizontal, and vertical), and a bilateral vertical-jump test.Results:Within-group analysis showed substantial improvements in all tests in both groups, with VUMD showing more robust adaptations in pooled COD tests and lateral/horizontal jumping, whereas the opposite occurred in CBV respecting linear sprinting and vertical jumping. Between-groups analyses showed substantially better results in lateral jumps (ES = 0.21), left-leg horizontal jump (ES = 0.35), and 10-m COD with right leg (ES = 0.42) in VUMD than in CBV. In contrast, left-leg countermovement jump (ES = 0.26) was possibly better in CBV than in VUMD.Conclusions:Eight weeks of EOT induced substantial improvements in functional-performance tests, although the force-vector application may play a key role to develop different and specific functional adaptations.
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Kondo, Narihiko, Manabu Shibasaki, Ken Aoki, Shunsaku Koga, Yoshimitsu Inoue, and Craig G. Crandall. "Function of human eccrine sweat glands during dynamic exercise and passive heat stress." Journal of Applied Physiology 90, no. 5 (May 1, 2001): 1877–81. http://dx.doi.org/10.1152/jappl.2001.90.5.1877.
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The purpose of this study was to identify the pattern of change in the density of activated sweat glands (ASG) and sweat output per gland (SGO) during dynamic constant-workload exercise and passive heat stress. Eight male subjects (22.8 ± 0.9 yr) exercised at a constant workload (117.5 ± 4.8 W) and were also passively heated by lower-leg immersion into hot water of 42°C under an ambient temperature of 25°C and relative humidity of 50%. Esophageal temperature, mean skin temperature, sweating rate (SR), and heart rate were measured continuously during both trials. The number of ASG was determined every 4 min after the onset of sweating, whereas SGO was calculated by dividing SR by ASG. During both exercise and passive heating, SR increased abruptly during the first 8 min after onset of sweating, followed by a slower increase. Similarly for both protocols, the number of ASG increased rapidly during the first 8 min after the onset of sweating and then ceased to increase further ( P > 0.05). Conversely, SGO increased linearly throughout both perturbations. Our results suggest that changes in forearm sweating rate rely on both ASG and SGO during the initial period of exercise and passive heating, whereas further increases in SR are dependent on increases in SGO.
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Simonnet, Émilie, and Isabelle Brunet. "Les fonctions de l’innervation sympathique artérielle." médecine/sciences 35, no. 8-9 (August 2019): 643–50. http://dx.doi.org/10.1051/medsci/2019131.
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L’innervation sympathique artérielle (ISA) est un processus biologique complexe nécessitant un guidage fin des axones des neurones sympathiques par les artères. L’ISA est un élément clé de l’adaptation du système cardiovasculaire aux différentes contraintes (exposition au froid, exercice, etc.) : elle contrôle le diamètre des artères de résistance, donc le flux sanguin parvenant aux organes et la pression artérielle systémique via la modulation du tonus artériel. Son importance lors du vieillissement et dans de nombreux contextes pathologiques est de mieux en mieux reconnue et comprise. Son intégration à la prise en charge de nombreuses maladies (hypertension, cancer, etc.) permettrait d’en améliorer traitements et pronostic.
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Hussain, S. N., R. L. Pardy, and J. A. Dempsey. "Mechanical impedance as determinant of inspiratory neural drive during exercise in humans." Journal of Applied Physiology 59, no. 2 (August 1, 1985): 365–75. http://dx.doi.org/10.1152/jappl.1985.59.2.365.
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Five healthy males exercised progressively with small 2-min increments in work load. We measured inspiratory drive (occlusion pressure, P0.1), pulmonary resistance (RL), dynamic pulmonary compliance (Cdyn), transdiaphragmatic pressure (Pdi), and diaphragmatic electromyogram (EMGdi). Minute ventilation (VE), mean inspiratory flow rate (VT/TI), and P0.1 all increased exponentially with increased work load, but P0.1 increased at a faster rate than did VT/TI or VE. Thus effective impedance (P0.1/VT/TI) rose throughout exercise. The increasing P0.1 was mostly due to augmented Pdi and coincided with increased EMGdi during this initial portion of inspiration. We found no consistent change in RL or Cdyn throughout exercise. With He breathing (80% He-20% O2), RL was reduced at all work loads; P0.1 fell in comparison with air-breathing values and VE, VT, and VT/TI rose in moderate and heavy work; and P0.1/VT/TI was unchanged with increasing exercise loads. Step reductions in gas density at a constant work load of any intensity showed an immediate reduction in the rate of rise of EMGdi and Pdi followed by increased VT/TI, breathing frequency, and hypocapnia. These changes were maintained during prolonged periods of unloading and were immediately reversible on return to air breathing. These data are consistent with the existence of a reflex effect on the magnitude of inspiratory neural drive during exercise that is sensitive to the load presented by the normal mechanical time constant of the respiratory system. This “load” is a significant determinant of the hyperpneic response and thus of the maintenance of normocapnia during exercise.
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De Bock, K., W. Derave, M. Ramaekers, E. A. Richter, and P. Hespel. "Fiber type-specific muscle glycogen sparing due to carbohydrate intake before and during exercise." Journal of Applied Physiology 102, no. 1 (January 2007): 183–88. http://dx.doi.org/10.1152/japplphysiol.00799.2006.
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The effect of carbohydrate intake before and during exercise on muscle glycogen content was investigated. According to a randomized crossover study design, eight young healthy volunteers ( n = 8) participated in two experimental sessions with an interval of 3 wk. In each session subjects performed 2 h of constant-load bicycle exercise (∼75% maximal oxygen uptake). On one occasion (CHO), they received carbohydrates before (∼150 g) and during (1 g·kg body weight−1·h−1) exercise. On the other occasion they exercised after an overnight fast (F). Fiber type-specific relative glycogen content was determined by periodic acid Schiff staining combined with immunofluorescence in needle biopsies from the vastus lateralis muscle before and immediately after exercise. Preexercise glycogen content was higher in type IIa fibers [9.1 ± 1 × 10−2 optical density (OD)/μm2] than in type I fibers (8.0 ± 1 × 10−2 OD/μm2; P < 0.0001). Type IIa fiber glycogen content decreased during F from 9.6 ± 1 × 10−2 OD/μm2 to 4.5 ± 1 × 10−2 OD/μm2 ( P = 0.001), but it did not significantly change during CHO ( P = 0.29). Conversely, in type I fibers during CHO and F the exercise bout decreased glycogen content to the same degree. We conclude that the combination of carbohydrate intake both before and during moderate- to high-intensity endurance exercise results in glycogen sparing in type IIa muscle fibers.
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Salvadego, Desy, Alessandro Sartorio, Fiorenza Agosti, Gabriella Tringali, Alessandra Patrizi, Miriam Isola, Antonella LoMauro, Andrea Aliverti, and Bruno Grassi. "Respiratory muscle endurance training reduces the O2 cost of cycling and perceived exertion in obese adolescents." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 313, no. 4 (October 1, 2017): R487—R495. http://dx.doi.org/10.1152/ajpregu.00396.2016.
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In obesity, the increased O2 cost of breathing negatively affects the O2 cost of exercise and exercise tolerance. The purpose of the study was to determine whether, in obese adolescents, the addition of respiratory muscle endurance training (RMET) (isocapnic hyperpnea) to a standard body mass reduction program decreases the O2 cost of exercise and perceived exertion. Nine male obese adolescents [16.0 ± 1.4 yr ( x ± SD), body mass 114.4 ± 22.3 kg] underwent 3 wk of RMET (5 days/week) in addition to a standard body mass reduction program. Eight age- and sex-matched obese adolescents underwent only the standard program (CTRL). Before and after interventions, patients performed on a cycle ergometer: incremental exercise; 12-min exercises at a constant work rate (CWR) of 65% and 120% at the gas exchange threshold (GET) determined before the intervention. Breath-by-breath pulmonary ventilation (V̇e) and O2 uptake (V̇o2), heart rate (HR), and ratings of perceived exertion for dyspnea/respiratory discomfort (RPER) and leg effort (RPEL) were determined. Body mass decreased (by ~3.0 kg) after both RMET ( P = 0.003) and CTRL ( P = 0.002). Peak V̇o2 was not affected by both interventions. Peak work rate was slightly, but significantly ( P = 0.04), greater after RMET but not after CTRL. During CWR < GET, no changes were observed after both interventions. During CWR > GET, the O2 cost of cycling at the end of exercise ( P = 0.02), the slope of V̇o2 vs. time (3–12 min) ( P = 0.01), RPER ( P = 0.01), and RPEL ( P = 0.01) decreased following RMET, but not following CTRL. HR decreased after both RMET ( P = 0.02) and CTRL ( P = 0.03), whereas V̇e did not change. In obese adolescents RMET, superimposed on a standard body mass reduction program, lowered the O2 cost of cycling and perceived exertion during constant heavy-intensity exercise.
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IWANAGA, Koichi, Kouichi SAIRYO, Tadao MINAMI, Masao SAKURAl, and Yoshiyuki KATO. "Change in Intracellular pH of Working Muscle during Constant and Stepwise Incremental Load Exercise." Annals of physiological anthropology 11, no. 4 (1992): 401–7. http://dx.doi.org/10.2114/ahs1983.11.401.
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Courtet, Philippe, Bénédicte Nobile, and Émilie Olié. "Soyons plus ambitieux pour traiter le suicide." médecine/sciences 36, no. 12 (December 2020): 1207–12. http://dx.doi.org/10.1051/medsci/2020229.
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Il est difficile de discuter de la mort sans parler de la mort volontaire. Le suicide est en effet un enjeu de santé publique majeur. Il est donc primordial de pouvoir identifier les sujets à risque et de les prendre en charge. Cependant, cet exercice reste complexe. Une première avancée est de considérer les conduites suicidaires (CS) comme une entité diagnostique à part entière avec sa propre physiopathologie. De nouvelles pistes de compréhension sont aussi nécessaires ; le rôle de la douleur tant physique que sociale dans le suicide est une voie prometteuse. Les traitements pharmacologiques actuels visent principalement à traiter les pathologies associées à ces conduites, mais certaines molécules ayant une action anti-suicidaire rapide et spécifique, comme la kétamine, se montrent encourageantes.
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Pepin, Véronique, Didier Saey, Claude H. Côté, Pierre LeBlanc, and François Maltais. "Susceptibility to Muscle Fatigue and Lung Mechanics in Chronic Obstructive Pulmonary Disease." Clinical & Investigative Medicine 30, no. 3 (June 1, 2007): 27. http://dx.doi.org/10.25011/cim.v30i3.1721.
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Background: Contractile fatigue of the quadriceps occurs in a significant proportion of patients with COPD after constant-load cycling exercise. Dynamic hyperinflation, by altering cardiac output during exercise, could contribute to fatigue susceptibility in this population. The purpose of this study was to compare operational lung volumes during constant workrate exercise between COPD patients who do and those who do not develop contractile fatigue of the quadriceps (fatiguers vs non-fatiguers).
Methods: Sixty-two patients with COPD (FEV1: 46±16%) completed a constant-load cycling test at 80% of the peak workrate achieved during progressive cycle ergometry. Ventilatory parameters were monitored breath-by-breath, while inspiratory capacity maneuvers were obtained every other minute during constant-load cycling. Quadriceps twitch force was measured with magnetic stimulation of the femoral nerve before and after the test. Muscle fatigue was defined as a post-exercise reduction in quadriceps twitch force of more than 15% of the resting value.
Results: Forty patients (65%) developed muscle fatigue after constant-load cycling. No significant differences were found between fatiguers and non-fatiguers with respect to age, body mass index, resting lung function, peak oxygen consumption, and endurance time to constant-load exercise. Change in inspiratory capacity from rest to end-exercise (DIC) was similar between both subgroups (DIC: 0.56±0.32L vs 0.56±0.47L for fatiguers and non-fatiguers respectively, P=0.99).
Conclusion: Susceptibility to muscle fatigue could not be predicted by exercise duration or by the degree of dynamic hyperinflation in patients with COPD.
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Guillemant, J., C. Accarie, G. Pérès, and S. Guillemant. "Effets aigus d’une charge calcique orale sur les marqueurs du métabolisme osseux pendant un exercice d’endurance sur cycle." Cahiers de Nutrition et de Diététique 39, no. 1 (February 2004): 66. http://dx.doi.org/10.1016/s0007-9960(04)94379-9.
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Johs, Nikolas A., Yvonne Kellar-Guenther, Catherine M. Jankowski, Hadlai Neff, and Kristine M. Erlandson. "A qualitative focus group study of perceived barriers and benefits to exercise by self-described exercise status among older adults living with HIV." BMJ Open 9, no. 3 (March 2019): e026294. http://dx.doi.org/10.1136/bmjopen-2018-026294.
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ObjectivesAlthough exercise interventions have been shown to improve health outcomes among older people with HIV (PLWH), this population remains highly sedentary. The purpose of this study was to examine the differences in perceived barriers and benefits of exercise among older PLWH by self-identified exercise status.DesignFive focus groups were formed among PLWH: two groups of exercising men, two groups of non-exercising men and one group of women (mixed exercisers and non-exercisers). Themes were analysed in relation to the social-ecological model, utilising the constant comparative approach.SettingPatients were recruited from an academic medical centre, HIV clinic and community locations.ParticipantsPLWH aged 50 or older, diagnosed with HIV for at least 2 years, with no other health conditions that would preclude exercise.Primary and secondary outcome measuresDetermine facilitators, barriers and the ideal environment for exercise or physical activity and determine whether these differ between older PLWH who self-identify as exercisers or non-exercisers.ResultsAmong 25 men (11 exercisers and 14 non-exercisers) and four women (three non-exercisers and one exerciser), non-exercisers mentioned fewer benefits of exercise (n=46) than exercisers (n=75). Exercisers emphasised positive reinforcement, positive mood change and increased energy as benefits of exercise; interpersonal benefits of exercise were also discussed twice as often by exercisers than by non-exercisers. Non-exercisers emphasised barriers to exercise including lack of motivation, lack of self-efficacy and a negative perception of gym culture. Non-exercisers identified the need for age-appropriate activities as a feature of an ideal exercise environment. Both groups identified time, cost and health-related challenges as barriers to exercise.ConclusionsUnique exercise barriers and benefits by self-identified exercise status provide important insights into the design of future interventions to initiate and maintain exercise.Trial registration numberNCT02404792; Results.
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Okawara, Hiroki, Tomonori Sawada, Daisuke Nakashima, Yuta Maeda, Shunsuke Minoji, Takashi Morisue, Yoshinori Katsumata, Morio Matsumoto, Masaya Nakamura, and Takeo Nagura. "Realtime Monitoring of Local Sweat Rate Kinetics during Constant-Load Exercise Using Perspiration-Meter with Airflow Compensation System." Sensors 22, no. 15 (July 22, 2022): 5473. http://dx.doi.org/10.3390/s22155473.
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Epidermal wearable sweat biomarker sensing technologies are likely affected by sweat rate because of the dilution effect and limited measurement methods. However, there is a dearth of reports on the local sweat rate (LSR) monitored in real-time during exercise. This explorative study investigated the feasibility of real-time LSR monitoring and clarified LSR kinetics on the forehead and upper arm during constant-load exercise using a perspiration meter with an airflow compensation system. This observational cross-sectional study included 18 recreationally trained males (mean age, 20.6 ± 0.8 years). LSR on the forehead and upper arm (mg/cm2/min) were measured during a constant-load exercise test at 25% of their pre-evaluated peak power until exhaustion. The LSR kinetics had two inflection points, with a gradual decrease in the incremental slope for each section. After the second flexion point, the LSR slope slightly decreased and was maintained until exhaustion. However, the degree of change varied among the participants. Although the ratio of forehead LSR to upper arm LSR tended to decrease gradually over time, there was little change in this ratio after a second flexion point of LSR in both. These findings suggest possible differences in LSR control between the forehead and upper arm during constant-load exercise to prolonged exhaustion.
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Heck, Kristen L., Jeffrey A. Potteiger, Karen L. Nau, and Jan M. Schroeder. "Sodium Bicarbonate Ingestion Does Not Attenuate the VO2 Slow Component during Constant-Load Exercise." International Journal of Sport Nutrition 8, no. 1 (March 1998): 60–69. http://dx.doi.org/10.1123/ijsn.8.1.60.
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We examined the effects of sodium bicarbonate ingestion on the VO2 slow component during constant-load exercise. Twelve physically active males performed two 30-min cycling trials at an intensity above the lactate threshold. Subjects ingested either sodium bicarbonate (BIC) or placebo (PLC) in a randomized. counterbalanced order. Arterialized capillary blood samples were analyzed for pH, bicarbonate concentration ([HCO3−), and lactate concentration ([La]). Expired gas samples were analyzed for oxygen consumption (VO2). The VO2 slow component was defined as the change in VO2 from Minutes 3 and 4 to Minutes 28 and 29. Values for pH and [HCO3−] were significantly higher for BIC compared to PLC. There was no significant difference in [La] between conditions. For both conditions there was a significant time effect for VO2 during exercise: however, no significant difference was observed between BIC and PLC. While extracellular acid-base measures were altered during the BIC trial, sodium bicarbonate ingestion did not attenuate the VO2 slow component during constant-load exercise.
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Yamazaki, F., R. Sone, and H. Ikegami. "Responses of sweating and body temperature to sinusoidal exercise." Journal of Applied Physiology 76, no. 6 (June 1, 1994): 2541–45. http://dx.doi.org/10.1152/jappl.1994.76.6.2541.
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This study determined the phase response and amplitude response (delta) of esophageal temperature (T(es)), mean skin temperature (Tsk), and forearm sweating rate (Msw) to sinusoidal work. Six healthy male subjects exercised on a cycle ergometer with a constant load (approximately 35% maximal O2 uptake) for a 30-min period; for the next 40 min they exercised with a sinusoidal load at 25 degrees C at 35% relative humidity. The sinusoidal load varied between approximately 10 and 60% maximal O2 uptake, and three different time periods (1.3, 4, and 8 min) were selected. Each subject performed three experiments that differed only in the timing of sinusoidal work. During the 4- and 8-min periods, T(es), Tsk, and Msw changed almost sinusoidally. The phase of Msw change significantly preceded those of T(es) and Tsk changes (P < 0.05). During the 1.3-min period, the level of T(es) and Tsk remained almost constant (delta T(es) 0.01 +/- 0.00 degrees C, delta Tsk 0.03 +/- 0.01 degrees C), whereas Msw showed a clear sinusoidal pattern. We conclude that the sweating response during sinusoidal work depends on both thermal and nonthermal factors, the latter being emotional, mental, or sensory stimulation. The contribution of the nonthermal factors to the general sweating response during exercise can be separated from that of the thermal factors by using sinusoidal work during a short period (e.g., 1.3 min).
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GOODMAN, Jack M., Peter R. McLAUGHLIN, and Peter P. LIU. "Left ventricular performance during prolonged exercise: absence of systolic dysfunction." Clinical Science 100, no. 5 (April 9, 2001): 529–37. http://dx.doi.org/10.1042/cs1000529.
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We assessed left ventricular systolic and diastolic performance during and after prolonged exercise under controlled conditions in a group of healthy, trained men. Previous studies have examined the effects of prolonged effort on left ventricular function, yet it remains unclear whether or not left ventricular dysfunction (e.g. cardiac fatigue) can be produced under such conditions. We studied 15 healthy men, aged 27±1 years (mean±S.E.M.). Subjects exercised on bicycles at a constant work rate (60% of maximum oxygen uptake per min) for 150 min. Measurements of gas exchange, blood pressure and haematocrit were obtained, concurrent with the assessment of left ventricular function using equilibrium radionuclide angiography, at rest, during exercise (every 30 min) and after 30 min of recovery. Fluid replacement was provided and monitored during the exercise period. The baseline resting and exercise ejection fractions were 66±2% and 78±2% respectively. During exercise, subjects consumed 1816±136 ml of fluid, and the haematocrit had increased at 120 min of exercise (from 47.2%±0.6 to 49.9±0.8%; P < 0.05). There was no change in either systolic or diastolic blood pressure throughout the exercise period, but heart rate drifted upwards from 141±2 beats/min after 30 min to 154±3 beats/min after 150 min (P < 0.05). There was a small decline (8%; P < 0.05) in end-diastolic volume at 150 min. No changes were observed in left ventricular ejection fraction, the pressure/volume ratio or end-systolic volume. After 30 min of sitting in recovery, heart rate was still higher than the pre-exercise value (84±3 compared with 69±2 beats/min; P < 0.05), as were measures of peak filling rate and time to peak filling (P < 0.05). The ejection fraction in the post-exercise recovery period was similar to the pre-exercise value. The results indicate that prolonged exercise of moderate duration may not induce abnormal left ventricular systolic function or cardiac fatigue during exercise.
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Hui, David, Liliana Larsson, Sajan Thomas, Carol Harrison, Jimin Wu, Donald Mahler, Kenneth R. Hess, et al. "Effect of high flow oxygen on exertional dyspnea in cancer patients: A double-blind randomized clinical trial." Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): 11600. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.11600.
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11600 Background: High flow oxygen therapy is effective for hypoxemic respiratory failure. However, its effect on dyspnea in non-hypoxemic patients is unknown. In this 2x2 factorial, double-blind randomized clinical trial, we assessed the effect of flow rate (high vs. low) and gas (oxygen vs. air) on exertional dyspnea in cancer patients. Methods: Non-hypoxemic patients with cancer completed two structured cycle ergometer exercise tests with Low Flow Air [LFAir] at 2 L/min. They were then randomized to receive High Flow Oxygen [HFOx] with up to 60 L/min, High Flow Air [HFAir], Low Flow Oxygen [LFOx] or LFAir during a constant work rate exercise test at 80% maximum. Dyspnea intensity was assessed with the modified 0-10 Borg scale. The primary outcome was difference in the slope of dyspnea intensity vs. time during the third test. Secondary outcomes included difference in exercise time, vital signs, and adverse events. We estimated that 10 patients per arm will provide 86% power to detect a 1-standard deviation main effect and 86% power to detect a 2-SD interaction effect with an alpha of 5%. A linear mixed effects model was used to assess the impact of flow rate and gas on study outcomes. Results: 45 patients were randomized and 44 completed the study (10, 11, 12, 11 patients on HFOx, HFAir, LFOx, LFAir, respectively). The mean age was 63 (range 47-77); 18 (41%) were female; 34 (44%) had lung cancer; and 20 (46%) had metastatic disease. In mixed effects model, the association between the change in dyspnea intensity over time with flow rate differed significantly between oxygen and air (P = 0.04). Specifically, HFOx (slope difference -0.20, P < 0.001) and LFOx (-0.14, P = 0.01) were significantly better than LFAir, but not HFAir (+0.09, P = 0.09). Exercise time also significantly increased with HFOx (difference +2.5 min, P = 0.009) compared to LFAir, but not HFAir (+0.63 min, P = 0.48) or LFOx (+0.39 min, P = 0.65). HFOx was well tolerated without significant adverse effects. Conclusions: The combination of high flow rate and oxygen improved dyspnea and exercise duration during constant work exercise test in non-hypoxemic cancer patients. Larger trials are needed to confirm the benefits of HFOx during exercises. Clinical trial information: NCT02357134.
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KHALILOV, V. R., and F. KH. CHIBIROVA. "EFFECT OF A CONSTANT UNIFORM MAGNETIC FIELD ON AN ELECTRON BOUND INTO A SINGULAR POTENTIAL." International Journal of Modern Physics A 21, no. 15 (June 20, 2006): 3171–79. http://dx.doi.org/10.1142/s0217751x06031405.
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The behavior of an electrically charged massive particle (an electron) is studied in a constant uniform magnetic field and a single attractive λδ(r) potential. A simple transcendental equation that determines the electron energy spectrum is derived. The approximate wave function of a loosely bound state is constructed in a very simple form. The model under consideration makes it possible to study the effect of magnetic fields on a loosely bound electron. It is shown that the sizes of the electron localization region change and the probability current density arises when the electron is in the loosely bound state in the presence of a constant uniform magnetic field. The above current must involve (and exercise influence on) the electron scattering. The probability current resembles a stack of "pancake vortices" whose circulating (around the z-axes) "currents" are mostly confined within the plane z = 0 in the weak magnetic field. The equation for determining the energy levels of the electron states is obtained for the model under study in two spatial dimensions and the energy of the loosely bound state is found for the two-dimensional model.
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Regensteiner, Judith G., Timothy A. Bauer, Jane E. B. Reusch, Suzanne L. Brandenburg, Jeffrey M. Sippel, Andria M. Vogelsong, Susan Smith, Eugene E. Wolfel, Robert H. Eckel, and William R. Hiatt. "Abnormal oxygen uptake kinetic responses in women with type II diabetes mellitus." Journal of Applied Physiology 85, no. 1 (July 1, 1998): 310–17. http://dx.doi.org/10.1152/jappl.1998.85.1.310.
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Persons with type II diabetes mellitus (DM), even without cardiovascular complications have a decreased maximal oxygen consumption (V˙o2 max) and submaximal oxygen consumption (V˙o2) during graded exercise compared with healthy controls. We evaluated the hypothesis that change in the rate ofV˙o2in response to the onset of constant-load exercise (measured byV˙o2-uptake kinetics) was slowed in persons with type II DM. Ten premenopausal women with uncomplicated type II DM, 10 overweight, nondiabetic women, and 10 lean, nondiabetic women had aV˙o2 maxtest. On two separate occasions, subjects performed 7-min bouts of constant-load bicycle exercise at workloads below and above the lactate threshold to enable measurements of V˙o2kinetics and heart rate kinetics (measuring rate of heart rate rise).V˙o2 maxwas reduced in subjects with type II DM compared with both lean and overweight controls ( P < 0.05). Subjects with type II DM had slowerV˙o2and heart rate kinetics than did controls at constant workloads below the lactate threshold. The data suggest a notable abnormality in the cardiopulmonary response at the onset of exercise in people with type II DM. The findings may reflect impaired cardiac responses to exercise, although an additional defect in skeletal muscle oxygen diffusion or mitochondrial oxygen utilization is also possible.
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McKay, Bryon R., Donald H. Paterson, and John M. Kowalchuk. "Effect of short-term high-intensity interval training vs. continuous training on O2 uptake kinetics, muscle deoxygenation, and exercise performance." Journal of Applied Physiology 107, no. 1 (July 2009): 128–38. http://dx.doi.org/10.1152/japplphysiol.90828.2008.
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The early time course of adaptation of pulmonary O2 uptake (V̇o2p) (reflecting muscle O2 consumption) and muscle deoxygenation kinetics (reflecting the rate of O2 extraction) were examined during high-intensity interval (HIT) and lower-intensity continuous endurance (END) training. Twelve male volunteers underwent eight sessions of either HIT (8–12 × 1-min intervals at 120% maximal O2 uptake separated by 1 min of rest) or END (90–120 min at 65% maximal O2 uptake). Subjects completed step transitions to a moderate-intensity work rate (∼90% estimated lactate threshold) on five occasions throughout training, and ramp incremental and constant-load performance tests were conducted at pre-, mid-, and posttraining periods. V̇o2p was measured breath-by-breath by mass spectrometry and volume turbine. Deoxygenation (change in deoxygenated hemoglobin concentration; Δ[HHb]) of the vastus lateralis muscle was monitored by near-infrared spectroscopy. The fundamental phase II time constants for V̇o2p (τV̇o2) and deoxygenation kinetics {effective time constant, τ′ = (time delay + τ), Δ[HHb]} during moderate-intensity exercise were estimated using nonlinear least-squares regression techniques. The τV̇o2 was reduced by ∼20% ( P < 0.05) after only two training sessions and by ∼40% ( P < 0.05) after eight training sessions (i.e., posttraining), with no differences between HIT and END. The τ′Δ[HHb] (∼20 s) did not change over the course of eight training sessions. These data suggest that faster activation of muscle O2 utilization is an early adaptive response to both HIT and lower-intensity END training. That Δ[HHb] kinetics (a measure of fractional O2 extraction) did not change despite faster V̇o2p kinetics suggests that faster kinetics of muscle O2 utilization were accompanied by adaptations in local muscle (microvascular) blood flow and O2 delivery, resulting in a similar “matching” of blood flow to O2 utilization. Thus faster kinetics of V̇o2p during the transition to moderate-intensity exercise occurs after only 2 days HIT and END training and without changes to muscle deoxygenation kinetics, suggesting concurrent adaptations to microvascular perfusion.
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Perrey, Stéphane, Jodie Scott, Laurent Mourot, and Jean-Denis Rouillon. "Cardiovascular and Oxygen Uptake Kinetics During Sequential Heavy Cycling Exercises." Canadian Journal of Applied Physiology 28, no. 2 (April 1, 2003): 283–98. http://dx.doi.org/10.1139/h03-022.
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The purpose of the present study was to assess the relationship between the rapidity of increased oxygen uptake [Formula: see text] and increased cardiac output (CO) during heavy exercise. Six subjects performed repeated bouts on a cycle ergometer above the ventilatory threshold (∼80% of peak [Formula: see text]) separated by 10-min recovery cycling at 35% peak [Formula: see text]. [Formula: see text] was determined breath-by-breath and CO was determined continuously by impedance cardiography. CO and [Formula: see text] values were significantly higher during the 2-min period preceding the second bout. The overall responses for [Formula: see text] and CO were significantly related and were faster during the second bout. Prior heavy exercise resulted in a significant increase in the amplitude of the fast component of [Formula: see text] with no change in the time constant and a decrease in the slow component. Under these circumstances, the amplitude of the fast component was more sensitive to prior heavy exercise than was the associated time constant. Key words: impedance cardiography, exercise transitions, cardiac output, prior exercise
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NGom, Stéphanie Esthelle Geneviève Minka, Caroline Kenmegne, Valentin Fokouo Fogha, Cedric Kuifo, and Louis Richard Njock. "Difficulté de la prise en charge de l’accident de décompression : à propos d’un cas vécu au Cameroun." Annales Africaines de Medecine 15, no. 1 (January 30, 2022): e4496-e4498. http://dx.doi.org/10.4314/aamed.v15i1.11.
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Decompression illness is a rare complication of scuba diving. We report the case of a 29-year-old military man who was admitted to Emergency Department of General Hospital Douala a few minutes after a diving exercise, with complete dysphagia, dysphonia, rotatory vertigo, gait and balance disorder, and severe neck pain radiating along the back. After an emergency treatment, check-ups revealed a cerebral-medullary infarction which confirms the diagnosis of severe decompression sickness. In the lack of hyperbaric oxygen, the patient received normobaric oxygen therapy, antiplatelet agent, hyperhydration and physiotherapy.
Les accidents de décompression (ADD) sont des complications rares au décours d’une plongée sous-marine. Nous rapportons le cas d’un militaire de 29 ans admis aux urgences de l’Hôpital Général Douala (HGD) quelques minutes après un exercice de plongée et qui a présenté une dysphagie complète, une dysphonie, des vertiges rotatoires, un trouble de la marche et de l’équilibre et des vives douleurs cervicales irradiant le long du dos. Après une prise en charge en urgence des bilans faits ont révélé un infarctus cérébromédullaire qui confirme le diagnostic d’accident de décompression sévère. En l’absence de l’oxygène hyperbare, le patient a été mis sous oxygénothérapie normobare, antiagrégant plaquettaire, hyperhydratation et physiothérapie.
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Romary, E., J. Marmin, and O. Castagna. "Bases physiopathogéniques de l’œdème pulmonaire d’immersion." Annales françaises de médecine d’urgence 10, no. 2 (January 12, 2020): 103–9. http://dx.doi.org/10.3166/afmu-2019-0210.
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L’œdème pulmonaire d’immersion (OPI) est souvent décrit en plongée en scaphandre autonome mais peut aussi s’observer en nage de surface ou en apnée sousmarine. Cette pathologie, directement liée aux contraintes environnementales de l’immersion, est favorisée par un terrain cardiovasculaire. Elle peut également toucher des cœurs sains à travers un exercice physique associé à un effort ventilatoire important. L’OPI a pour origine une augmentation du gradient de pression transmurale au niveau des capillaires pulmonaires par une élévation de la pression capillaire (précharge et postcharge) et une diminution de la pression alvéolaire. Au travers d’un cas clinique, nous précisons les mécanismes physiopathologiques encore méconnus de ce déséquilibre pressionnel et nous décrivons les principes de prise en charge préhospitalière et hospitalière de l’OPI avec un rappel des diagnostics différentiels à évoquer devant une symptomatologie respiratoire au décours d’une plongée. Nous insistons sur une sensibilisation et un dépistage cardiologique d’un terrain à risque, en particulier d’une hypertension artérielle, chez tout plongeur de plus de 50 ans.
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Gerbino, A., S. A. Ward, and B. J. Whipp. "Effects of prior exercise on pulmonary gas-exchange kinetics during high-intensity exercise in humans." Journal of Applied Physiology 80, no. 1 (January 1, 1996): 99–107. http://dx.doi.org/10.1152/jappl.1996.80.1.99.
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The effects of prior exercise on O2 uptake (VO2) kinetics during supra-lactate threshold (LT) cycling were assessed in 11 subjects. Protocols consisted of two consecutive 6-min work bouts separated by 0 W (6 min) with 1) both bouts sub-LT, 2) both bouts supra-LT, 3) bout 1 sub-LT and bout 2 supra-LT, and 4) bout 1 supra-LT and bout 2 sub-LT. Sub-LT VO2 kinetics were similar whether the prior bout was supra- or sub-LT. The VO2 kinetics for supra-LT work preceded by a sub-LT “warm-up” were similar to those for supra-LT work that was not preceded by exercise (O-W warm-up): the “partial”: O2 deficit averaged 2.64 vs. 2.57 liters, and the “effective” VO2 time constant averaged 56 vs. 65 s. Exercise responses (i.e., the change between O W and minute 6 of exercise) were unaffected for lactate concentration (4.58 vs. 4.50 meq/l), pH (-0.08 vs. -0.10), and CO2 output (VCO2; 2.65 vs. 2.49 l/min). However, when the supra-LT work was preceded by a supra-LT warm-up, VO2 kinetics were appreciably faster (O2 deficit = 1.82 liters, VO2 time constant = 37 s) relative to 0-W warm-up; the lactate (0.69 meq/l), pH (-0.01), and VCO2 (2.08 l/min) responses were smaller; and the effective VCO2 time constant was longer (58 vs. 43 s). The mechanism(s) that underlie this speeding of the VO2 kinetics cannot be firmly established, but we suggest that an improved muscle perfusion during the exercise may be involved consequent to the residual metabolic acidemia from the high-intensity warm-up.
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Miki, Keisuke, Kazuyuki Tsujino, Mari Miki, Kenji Yoshimura, Hiroyuki Kagawa, Yohei Oshitani, Kiyoharu Fukushima, Takanori Matsuki, Yuji Yamamoto, and Hiroshi Kida. "Managing COPD with expiratory or inspiratory pressure load training based on a prolonged expiration pattern." ERJ Open Research 6, no. 3 (July 2020): 00041–2020. http://dx.doi.org/10.1183/23120541.00041-2020.
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BackgroundExertional prolonged expiration should be identified as a therapeutic target in COPD. The efficacy of expiratory or inspiratory pressure load training (EPT/IPT) based on the degree of prolonged expiration was investigated.MethodsA total of 21 patients with COPD were divided into two groups according to the exertional change in the inspiratory duty cycle (TI/Ttot). For 12 weeks, patients whose exertional TI/Ttot decreased received EPT (EPT group, n=11, mean percentage forced expiratory volume in 1 s (%FEV1), 32.8%) and those whose exertional TI/Ttot increased received IPT (IPT group, n=10, mean %FEV1, 45.1%).ResultsThe therapeutic responses were as follows. In both groups, endurance time (EPT, +5.7 min, p<0.0001; IPT, +6.1 min, p=0.0004) on the constant work rate exercise test (WRET) and peak oxygen uptake increased (EPT, p=0.0028; IPT, p=0.0072). In the EPT group the following occurred: 1) soon after commencement of exercise with the constant WRET, the expiratory tidal volume (VTex) increased, reducing dyspnoea; 2) VTex and mean expiratory flow increased and then prolonged expiration (p=0.0001) improved at peak exercise with the incremental exercise test (ET); and 3) St. George's Respiratory Questionnaire total, activity and impact scores were improved. In the IPT group, on both the constant WRET and incremental ET, breathing frequency increased, which led to greater exercise performance with effort dyspnoea.ConclusionsThis study showed the benefits of EPT/IPT on exercise performance. If the choice of managing COPD with EPT/IPT is appropriate, inexpensive EPT/IPT may become widespread as home-based training.
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Tahara, Nobuhiro, Hiroshi Takaki, Atsushi Taguchi, Kazuhiro Suyama, Takashi Kurita, Wataru Shimizu, Shunichi Miyazaki, Toru Kawada, and Kenji Sunagawa. "Pronounced HR variability after exercise in inferior ischemia: evidence that the cardioinhibitory vagal reflex is invoked by exercise-induced inferior ischemia." American Journal of Physiology-Heart and Circulatory Physiology 288, no. 3 (March 2005): H1179—H1185. http://dx.doi.org/10.1152/ajpheart.00045.2004.
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Potent cardioinhibitory vagal reflex resulting in bradycardia and hypotension has been observed under particular conditions of transmural inferior ischemia and its reperfusion, such as those observed with acute infarction. However, whether exercise-induced ischemia with ST depressions that is subendocardial and that might be recurrently experienced in daily activities can evoke this reflex remains unknown. In patients with exercise-induced ST depressions due to either inferior [right coronary artery stenosis (RCA), n = 52] or anterior ischemia [left anterior descending artery stenosis (LAD), n = 51], we evaluated post exercise vagal activity (from 0 to 6 min) by the time constant of heart rate (HR) decay and HR variability by 30-s averages of the absolute values of successive RR interval differences (ΔRR). Exercise parameters were similar between groups. The time constant was slightly but significantly shorter in RCA than LAD patients (79 ± 24 vs. 93 ± 29 s, P < 0.01). More significantly, ΔRR early after exercise (0.5–2.5 min) was approximately twofold greater in RCA than LAD patients (from +76 to +118%, P < 0.001), indicating pronounced vagal activity stimulated by inferior ischemia. Revascularization prolonged the time constant ( P < 0.05) and attenuated recovery ΔRR in RCA patients ( P < 0.05, n = 10) but did not change both parameters in LAD patients ( n = 12). As well as acute inferior infarction, exercise-induced inferior subendocardial ischemia, which might recurrently occur in daily activities, activates the cardioinhibitory reflex. These new findings must be taken into account in interpreting vagal activity in patients with coronary artery disease.
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Wolfel, E. E., B. M. Groves, G. A. Brooks, G. E. Butterfield, R. S. Mazzeo, L. G. Moore, J. R. Sutton, et al. "Oxygen transport during steady-state submaximal exercise in chronic hypoxia." Journal of Applied Physiology 70, no. 3 (March 1, 1991): 1129–36. http://dx.doi.org/10.1152/jappl.1991.70.3.1129.
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Arterial O2 delivery during short-term submaximal exercise falls on arrival at high altitude but thereafter remains constant. As arterial O2 content increases with acclimatization, blood flow falls. We evaluated several factors that could influence O2 delivery during more prolonged submaximal exercise after acclimatization at 4,300 m. Seven men (23 +/- 2 yr) performed 45 min of steady-state submaximal exercise at sea level (barometric pressure 751 Torr), on acute ascent to 4,300 m (barometric pressure 463 Torr), and after 21 days of residence at altitude. The O2 uptake (VO2) was constant during exercise, 51 +/- 1% of maximal VO2 at sea level, and 65 +/- 2% VO2 at 4,300 m. After acclimatization, exercise cardiac output decreased 25 +/- 3% compared with arrival and leg blood flow decreased 18 +/- 3% (P less than 0.05), with no change in the percentage of cardiac output to the leg. Hemoglobin concentration and arterial O2 saturation increased, but total body and leg O2 delivery remained unchanged. After acclimatization, a reduction in plasma volume was offset by an increase in erythrocyte volume, and total blood volume did not change. Mean systemic arterial pressure, systemic vascular resistance, and leg vascular resistance were all greater after acclimatization (P less than 0.05). Mean plasma norepinephrine levels also increased during exercise in a parallel fashion with increased vascular resistance. Thus we conclude that both total body and leg O2 delivery decrease after arrival at 4,300 m and remain unchanged with acclimatization as a result of a parallel fall in both cardiac output and leg blood flow and an increase in arterial O2 content.(ABSTRACT TRUNCATED AT 250 WORDS)
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Verbree, J., AGT Bronzwaer, MA van Buchem, MJAP Daemen, JJ van Lieshout, and MJP van Osch. "Middle cerebral artery diameter changes during rhythmic handgrip exercise in humans." Journal of Cerebral Blood Flow & Metabolism 37, no. 8 (January 1, 2016): 2921–27. http://dx.doi.org/10.1177/0271678x16679419.
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Transcranial Doppler (TCD) sonography is a frequently employed technique for quantifying cerebral blood flow by assuming a constant arterial diameter. Given that exercise increases arterial pressure by sympathetic activation, we hypothesized that exercise might induce a change in the diameter of large cerebral arteries. Middle cerebral artery (MCA) cross-sectional area was assessed in response to handgrip exercise by direct magnetic resonance imaging (MRI) observations. Twenty healthy subjects (11 female) performed three 5 min bouts of rhythmic handgrip exercise at 60% maximum voluntary contraction, alternated with 5 min of rest. High-resolution 7 T MRI scans were acquired perpendicular to the MCA. Two blinded observers manually determined the MCA cross-sectional area. Sufficient image quality was obtained in 101 MCA-scans of 19 subjects (age-range 20–59 years). Mixed effects modelling showed that the MCA cross-sectional area decreased by 2.1 ± 0.8% (p = 0.01) during handgrip, while the heart rate increased by 11 ± 2% (p < 0.001) at constant end-tidal CO2 (p = 0.10). In conclusion, the present study showed a 2% decrease in MCA cross-sectional area during rhythmic handgrip exercise. This further strengthens the current concept of sympathetic control of large cerebral arteries, showing in vivo vasoconstriction during exercise-induced sympathetic activation. Moreover, care must be taken when interpreting TCD exercise studies as diameter constancy cannot be assumed.
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Perrey, S., A. Betik, R. Candau, J. D. Rouillon, and R. L. Hughson. "Comparison of oxygen uptake kinetics during concentric and eccentric cycle exercise." Journal of Applied Physiology 91, no. 5 (November 1, 2001): 2135–42. http://dx.doi.org/10.1152/jappl.2001.91.5.2135.
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O2 uptake (V˙o 2) kinetics and electromyographic (EMG) activity from the vastus medialis, rectus femoris, biceps femoris, and medial gastrocnemius muscles were studied during constant-load concentric and eccentric cycling. Six healthy men performed transitions from baseline to high-intensity eccentric (HE) exercise and to high-intensity (HC), moderate-intensity (MC), and low-intensity (LC) concentric exercise. For HE and HC exercise, absolute work rate was equivalent. For HE and LC exercise,V˙o 2 was equivalent.V˙o 2 data were fit by a two- or three-component exponential model. Surface EMG was recorded during the last 12 s of each minute of exercise to obtain integrated EMG and mean power frequency. Only in the HC exercise didV˙o 2 increase progressively with evidence of a slow component ( phase 3), and only in HC exercise was there evidence of a coincident increase with time in integrated EMG of the vastus medialis and rectus femoris muscles ( P < 0.05) with no change in mean power frequency. The phase 2time constant was slower in HC [24.0 ± 1.7 (SE) s] than in HE (14.7 ± 2.8 s) and LC (16.7 ± 2.2 s) exercise, while it was not different from MC exercise (20.6 ± 2.1 s). These results show that the rate of increase inV˙o 2 at the onset of exercise was not different between HE and LC exercise, where the metabolic demand was similar, but both had significantly faster kinetics forV˙o 2 than HC exercise. TheV˙o 2 slow component might be related to increased muscle activation, which is a function of metabolic demand and not absolute work rate.
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Saitoh, Tadashi, Leonardo F. Ferreira, Thomas J. Barstow, David C. Poole, Anna Ooue, Narihiko Kondo, and Shunsaku Koga. "Effects of prior heavy exercise on heterogeneity of muscle deoxygenation kinetics during subsequent heavy exercise." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 297, no. 3 (September 2009): R615—R621. http://dx.doi.org/10.1152/ajpregu.00048.2009.
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We investigated the effects of prior heavy exercise on the spatial heterogeneity of muscle deoxygenation kinetics and the relationship to the pulmonary O2 uptake (pV̇o2) kinetics during subsequent heavy exercise. Seven healthy men completed two 6-min bouts of heavy work rate cycling exercise, separated by 6 min of unloaded exercise. The changes in the concentration of deoxyhemoglobin/myoglobin (Δdeoxy-[Hb+Mb]) were assessed simultaneously at 10 different sites on the rectus femoris muscle using multichannel near-infrared spectroscopy. Prior exercise had no effect on either the time constant or the amplitude of the primary component pV̇o2, whereas it reduced the amplitude of the slow component (SC). ΔDeoxy-[Hb+Mb] across all 10 sites for bout 2 displayed a shorter time delay (mean and SD for subjects: 13.5 ± 1.3 vs. 9.3 ± 1.4 s; P < 0.01) and slower primary component time constant (τ: 9.3 ± 1.3 vs. 17.8 ± 1.0 s; P < 0.01) compared with bout 1. Prior exercise significantly reduced both the intersite coefficient of variation (CV) of the τ of Δdeoxy-[Hb+Mb] (26.6 ± 11.8 vs. 13.7 ± 5.6%; P < 0.01) and the point-by-point heterogeneity [root mean square error (RMSE)] during the primary component in the second bout. However, neither the change in the CV for τ nor RMSE of Δdeoxy-[Hb+Mb] correlated with the reduction in the SC in pV̇o2 kinetics during subsequent heavy exercise. In conclusion, prior exercise reduced the spatial heterogeneity of the primary component of muscle deoxygenation kinetics. This effect was not correlated with alterations in the pV̇o2 response during subsequent heavy exercise.
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Leiper, J. B., K. McCormick, J. D. Robertson, P. H. Whiting, and R. J. Maughan. "Fluid homoeostasis during prolonged low-intensity walking on consecutive days." Clinical Science 75, no. 1 (July 1, 1988): 63–70. http://dx.doi.org/10.1042/cs0750063.
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1. The effect on fluid homoeostasis of walking 37 km on each of 4 consecutive relatively cool days was studied in six male subjects. The daily exercise intensity was consistent and was equivalent to 17(1)% [mean (se)] of maximum oxygen uptake for these subjects. 2. The diet during the study consisted of a mainly carbohydrate breakfast, consumed immediately before each day‘s exercise, and unrestricted access to a normal mixed diet after completion of each day's exercise. Water was allowed ad libitum during the walk. Food and fluid intake were recorded. 3. Body weight remained constant over the 4-day walk. The difference between total daily fluid intake and the corresponding 24 h urine output was 1684 (250) ml, 1621 (522) ml, 1107 (252) ml and 1406 (208) ml, respectively, on each of the 4 exercise days. 4. There was a calculated increase of 21.3(6.6)% in plasma volume over the 4-day walk; the largest daily change [11.3(2.9)%] occurred during the walk on day 1. The increase in plasma volume was maintained for at least 4 days after completion of the walk. 5. From day 2, serum sodium concentration tended to increase during the exercise period and fell to the pre-exercise concentration during the overnight rest periods. The concentration of the other measured serum constituents remained relatively constant, and serum osmolality did not alter over the study period.
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Imamdad, P., S. Turquier, P. Surpas, V. Cottin, J. Cordier, and J. Glerant. "Intérêt d’un test d’exercice à charge constante chez les patients présentant une fibrose pulmonaire idiopathique." Revue des Maladies Respiratoires 33 (January 2016): A62—A63. http://dx.doi.org/10.1016/j.rmr.2015.10.711.
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Tregub, Ganna. "Protestantism in the light of the conceptual foundations of diversification theory." Ukrainian Religious Studies, no. 69 (May 16, 2014): 60–70. http://dx.doi.org/10.32420/2014.69.380.
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Protestantism in the light of the conceptual foundations of diversification theory. Current article considers Protestantism from the perspective of the main principles of the theory of diversification, including a change and forms variability as a prerequisite for real exercise "held constant through change." It is shown that the preservation and transmission of religious, particularly Protestant, tradition is a complex process in which an important role is played by various factors shaping by the multiform etymologies
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Lorino, A. M., M. Meignan, P. Bouissou, and G. Atlan. "Effects of sustained exercise on pulmonary clearance of aerosolized 99mTc-DTPA." Journal of Applied Physiology 67, no. 5 (November 1, 1989): 2055–59. http://dx.doi.org/10.1152/jappl.1989.67.5.2055.
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The effects of intensive prolonged exercise on the pulmonary clearance rate of aerosolized 99mTc-labeled diethylenetriaminepentaacetate (99mTc-DTPA) and pulmonary mechanics were studied in seven healthy nonsmoking volunteers. 99mTc-DTPA clearance and pulmonary mechanics (lung volumes and compliance) were assessed before and after 75 min of constant-load exercise performed on a treadmill, corresponding to 75% of maximal O2 uptake. Because both clearance measurements were made in similar conditions of pulmonary blood flow, respiratory rate, and tidal volume, changes in clearance rate can be assumed to represent changes of alveolar epithelial permeability. After exercise, total, apical, and basal clearance were significantly increased (P less than 0.01, 0.05, and 0.05, respectively) and the increases in total clearance and tidal volume observed during exercise were significantly correlated (P less than 0.05). In contrast, no significant change was found in pulmonary mechanics. These results show that prolonged intensive exercise induces an increase in epithelial permeability, which appears to be related to the mechanical effects of sustained increased ventilation. Because no change was evidenced in pulmonary volumes or in lung elasticity, our results suggest that this increase may result from alteration of the intercellular tight junctions rather than from a surfactant deficiency.
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Hirsch, Mikeal. "Future planning for capacity in plant pathology." Microbiology Australia 33, no. 1 (2012): 3. http://dx.doi.org/10.1071/ma12003.
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We are all familiar with the three constants of life: death, taxes ? and strategic planning. As professionals, we are frequently getting involved in developing vision statements, strategies for change, action plans, performance indicators, impact metrics, review processes and so on. Strategic planning goes in cycles. At the national level we are now engaged in a new exercise, setting broad directions for the future of rural research and, in particular, biosecurity science. This is likely to impact on the future of professionals in microbiology and beyond. As always with these exercises, it is the ?journey? rather than the ?destination? that is important, as it enables us to take stock and reflect on where we are heading in terms of future capacity. This paper outlines some of these planning activities and earlier findings, with a focus on future capacity in plant pathology, but the lessons apply to all readers of this journal. It is important that members of the Australian Society for Microbiology (ASM) and other professional societies engage in these strategic planning efforts to shape our own future.
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Crouse, S. F., B. C. O'Brien, J. J. Rohack, R. C. Lowe, J. S. Green, H. Tolson, and J. L. Reed. "Changes in serum lipids and apolipoproteins after exercise in men with high cholesterol: influence of intensity." Journal of Applied Physiology 79, no. 1 (July 1, 1995): 279–86. http://dx.doi.org/10.1152/jappl.1995.79.1.279.
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The purpose of this study was to characterize the short-term changes in blood lipid and apolipoprotein concentrations in healthy hypercholesterolemic men after high-intensity [80% maximal O2 uptake (VO2max); n = 20] or moderate-intensity (50% VO2max; n = 19) cycle ergometer exercise balanced for caloric expenditure (350 kcal). The men's age, height, weight, %fat, and VO2max were 46 +/- 2 yr, 173 +/- 7 cm, 82.7 +/- 2.2 kg, 28 +/- 1%, and 31.1 +/- 1.0 ml O2.kg-1.min-1, respectively. Blood samples were drawn before exercise, immediately after exercise, then 24 and 48 h later, and concentrations of all variables were adjusted for changes in plasma volume. Significant changes (P < 0.0016) were as follows: total and low-density lipoprotein cholesterol fell by 4% immediately after exercise and then rose by 5–8% by 48 h. Triglycerides were 18 and 15% lower at 24 and 48 h, respectively. HDL-cholesterol, high-density lipoprotein3-cholesterol, and apolipoprotein B rose 8–9% by 24 h and remained elevated. High-density lipoprotein2-cholesterol rose by 27% by 48 h after exercise, but this change was not significant. Apolipoprotein A-I did not change with exercise. The response patterns were not affected by exercise intensity. These data show that a single session of exercise performed by untrained hypercholesterolemic men alters blood lipid and apolipoprotein concentrations. Furthermore, the postexercise response patterns are not influenced by exercise intensity, as long as caloric expenditure is held constant.
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Berardi, Giovanni, Grace Ptizen, Matthew DellaIacono, and Marie Hoeger Bement. "4095 Concurrent assessment of experimental pain and self-reported pain intensity with acute exercise intervention in fibromyalgia; clarifying or obscuring clinical outcomes?" Journal of Clinical and Translational Science 4, s1 (June 2020): 94. http://dx.doi.org/10.1017/cts.2020.294.
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OBJECTIVES/GOALS: Experimental pain testing is used to identify changes in nociceptive processing and outcomes with intervention. This study investigated exercise induced changes in experimental pain and self-reported pain intensity after an acute bout of exercise in participants with fibromyalgia. METHODS/STUDY POPULATION: Ten females with fibromyalgia (55±10yr) were familiarized to study procedures and underwent submaximal (20% maximal voluntary contraction) intermittent eccentric muscle contractions isolated to the right arm for 10-minutes. Self-reported pain intensity (0-10 numerical pain rating scale [NPRS]) of the exercising arm was measured before, during, and after exercise; whole-body pain intensity was measured before and after exercise. Experimental pain testing included measurement of pressure pain thresholds (kPa [PPTs]); temporal summation (TS) of pressure pain with a constant mechanical pressure; and TS of punctate pressure with repeated application of monofilaments before and after exercise. RESULTS/ANTICIPATED RESULTS: Participants reported minimal to moderate arm pain (3.1±2.1) during exercise. Following exercise, arm pain and whole-body pain significantly increased (3.1±2.2 and 1.6±0.5, respectively) [p<0.05]. No change occurred with PPTs at the bicep (138.9±49.5 to 142.8±55.3), PPTs at the quad (212.0±105.4 to 228.1±100.0), TS of mechanical pressure pain (7.6±2.1 to 7.9±1.5), TS of punctate pressure pain at the bicep (2.6±1.7 to 3.0±1.5), and TS of punctate pressure pain at the quad (3.6±1.5 to 3.7±1.4) before to after exercise respectively [p>0.05]. The change in self-reported arm and whole-body pain did not correlate with the change in experimental pain testing. DISCUSSION/SIGNIFICANCE OF IMPACT: In people with fibromyalgia, there is no relation between self-reported clinical pain and experimental pain following a single exercise session. Further research should identify the influence of exercise training on pain perception and if experimental pain testing translates to clinical insight.
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Rowland, Thomas, David Pober, and Anne Garrison. "Cardiovascular drift in euhydrated prepubertal boys." Applied Physiology, Nutrition, and Metabolism 33, no. 4 (August 2008): 690–95. http://dx.doi.org/10.1139/h08-031.
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“Classic” cardiovascular drift is characterized by findings of decreasing stroke volume and mean arterial pressure, rising heart rate, and stable cardiac output during sustained constant-load exercise. Recent studies in adults indicate that when dehydration is prevented by fluid intake, this pattern is altered, with no change in stroke volume and progressive rise in cardiac output. This study was designed to examine this influence of hydration in prepubertal subjects and assess the relationship between cardiovascular drift and aerobic drift (changes in VO2). Eight boys (Tanner stage 1, mean age 11.7 ± 0.4 y) cycled at an average of 62.9% ± 3.9% VO2 peak to exhaustion (41.38 ± 6.30 min) in a thermoneutral environment. Rectal temperature rose from 37.6 ± 0.1 °C at rest to 38.1 ± 0.2 °C at end exercise. Between 5 min and end exercise, average heart rate rose by 13.2% and cardiac output rose by 14.9%, systemic vascular resistance fell by 10.5%, and stroke volume remained stable. Increases in cardiac output paralleled those of VO2, with no change in arterial venous oxygen difference. These findings are consistent with the conclusion that cardiovascular drift is a reflection of aerobic drift, a relationship obscured by the superimposed physiological effects of dehydration during sustained constant load. This study also suggests that such patterns are no different in prepubertal boys and young adult men.
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Cognet, Marguerite. "Les femmes, les services et le don." Cahiers de recherche sociologique, no. 37 (April 28, 2011): 51–77. http://dx.doi.org/10.7202/1002318ar.
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Nos travaux sur les pratiques des infirmières et des auxiliaires familiales mettent en évidence l’engagement des femmes dans des activités de soins et services qui sont loin d’être les plus valorisées. Nous reprendrons ici les résultats de l’étude concernant les auxiliaires familiales et sociales de Montréal exerçant en maintien à domicile soit au compte du service public (par le biais des CLSC) soit à celui du secteur marchand (par le biais des agences privées). Alors que les contraintes physiques de leur métier, la charge émotionnelle sont fortes, qu’une grande part des compétences qu’elles déploient est maintenue dans l’invisible — la position socioprofessionnelle, et la hauteur de la rémunération qui l’accompagne, président à une mise en forme formelle de compétences (liste de tâches) aisément quantifiables mais peu valorisées et peu valorisantes — et que leur exercice est toujours l’objet d’une faible considération sociale, ces intervenantes en font souvent plus qu’il ne leur est demandé, déclarent aimer leur travail, ont un sentiment fort de réalisation de soi. Ces résultats ne sont compréhensibles que si nous les considérons sous l’angle de l’engagement et du don de soi.