Journal articles on the topic 'Power training frequency'
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Tavares, Lucas D., Eduardo Oliveira De Souza, Carlos Ugrinowitsch, Gilberto Candido Laurentino, Hamilton Roschel, and Valmor Tricoli. "Effect Of Training Frequency On Muscle Mass, Strength And Power Performance During Reduced Resistance Training." Medicine & Science in Sports & Exercise 48 (May 2016): 475. http://dx.doi.org/10.1249/01.mss.0000486429.41955.81.
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Lee, Myeong Soo, Hwa Jeong Huh, Byung Gi Kim, Hoon Ryu, Ho-Sub Lee, Jong-Moon Kim, and Hun-Tae Chung. "Effects of Qi-Training on Heart Rate Variability." American Journal of Chinese Medicine 30, no. 04 (January 2002): 463–70. http://dx.doi.org/10.1142/s0192415x02000491.
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This study investigates changes in autonomic nervous function through Qi-training. The power spectrum of heart rate variability (HRV) was examined in 20 sedentary healthy subjects and 20 Qi-trainees. It was found that Qi-training in healthy young subjects during controlled respiration increases the high frequency (HF) power and decreases the low frequency / high frequency (LF/HF) power ratio of HRV. These results support the hypothesis that Qi-training increases cardiac parasympathetic tone. In addition, Qi-trainees were found to have higher parasympathetic heart modulation compared with their age-matched, sedentary counterparts. This augmented HRV in Qi-trainees provides further support for long-term Qi-training as a possible non-pharmacological cardio-protective maneuver. In conclusion, Qi-training may stabilize the autonomic nervous system by modulating the parasympathetic nervous system.
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Cardinale, Marco. "High-frequency vibration training able to increase muscle power in postmenopausal women." Archives of Physical Medicine and Rehabilitation 85, no. 4 (April 2004): 687–88. http://dx.doi.org/10.1016/j.apmr.2004.01.015.
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Cui, Chunhai, Enqian Xin, Meili Qu, and Shuai Jiang. "Fatigue and Abnormal State Detection by Using EMG Signal During Football Training." International Journal of Distributed Systems and Technologies 12, no. 2 (April 2021): 13–23. http://dx.doi.org/10.4018/ijdst.2021040102.
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This paper proposes to monitor and recognize the fatigue state during football training by analyzing the surface electromyography (EMG) signals. The surface electromyography (EMG) signal is closely connected with the state during sports and training. First, power frequency interference, motion artifacts, and baseline drift in the surface electromyography (EMG) signal are removed; second, the authors extract 6 features: rectified average value (ARV), integrated electromyography myoelectric value (IEMG), root mean square of electromyography value (RMS), median frequency (MF), average power frequency (MPF), and electromyography power (TP) to represent the surface electromyography (EMG) signal; lastly, the extracted features are input into a one-class support vector machine to determine whether the player has been fatigued and are input into a weighted support vector machine to determine the degree of fatigue if the player has been fatigued. The experimental results show that more than 95% of the fatigue state can be recognized by surface electromyography (EMG) signal.
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Stengel, S. V., W. Kemmler, R. Pintag, C. Beeskow, J. Weineck, D. Lauber, W. A. Kalender, and K. Engelke. "Power training is more effective than strength training for maintaining bone mineral density in postmenopausal women." Journal of Applied Physiology 99, no. 1 (July 2005): 181–88. http://dx.doi.org/10.1152/japplphysiol.01260.2004.
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Physical exercise has a favorable impact on bones, but optimum training strategies are still under discussion. In this study, we compared the effect of slow and fast resistance exercises on various osteodensitometric parameters. Fifty-three postmenopausal women were randomly assigned to a strength training (ST) or a power training group (PT). Both groups carried out a progressive resistance training, a gymnastics session, and a home training over a period of 12 mo. During the resistance training, the ST group used slow and the PT group fast movements; otherwise there were no training differences. All subjects were supplemented with Ca and vitamin D. At baseline and after 12 mo, bone mineral density (BMD) was measured at the lumbar spine, proximal femur, and distal forearm by dual-energy X-ray absorptiometry. We also measured anthropometric data and maximum static strength. Frequency and grade of pain were assessed by questionnaire. After 12 mo, significant between-group differences were observed for BMD at the lumbar spine ( P < 0.05) and the total hip ( P < 0.05). Whereas the PT group maintained BMD at the spine (+0.7 ± 2.1%, not significant) and the total hip (0.0 ± 1.7%, not significant), the ST group lost significantly at both sites (spine: −0.9 ± 1.9%; P < 0.05; total hip: −1.2 ± 1.5%; P < 0.01). No significant between-group differences were observed for anthropometric data, maximum strength, BMD of the forearm, or frequency and grade of pain. These findings suggest that power training is more effective than strength training in reducing bone loss in postmenopausal women.
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Hu, Wenping, Jifeng Liang, Yitao Jin, Fuzhang Wu, Xiaowei Wang, and Ersong Chen. "Online Evaluation Method for Low Frequency Oscillation Stability in a Power System Based on Improved XGboost." Energies 11, no. 11 (November 21, 2018): 3238. http://dx.doi.org/10.3390/en11113238.
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Low frequency oscillation in an interconnected power system is becoming an increasingly serious problem. It is of great practical significance to make online evaluation of actual power grid’s stability. To evaluate the stability of the power system quickly and accurately, a low frequency oscillation stability evaluation method based on an improved XGboost algorithm and power system random response data is proposed in this paper. Firstly, the original input feature set describing the dynamic characteristics of the power system is established by analyzing the substance of low frequency oscillation. Taking the random response data of power system including the disturbance end time feature and the dynamic feature of power system as the input sample set, the wavelet threshold is applied to improve its effectiveness. Secondly, using the eigenvalue analysis method, different damping ratios are selected as threshold values to judge the stability of the system low-frequency oscillation. Then, the supervised training with improved XGboost algorithm is performed on the characteristics of stability. On this basis, the training model is obtained and applied to online low frequency oscillation stability evaluation of a power system. Finally, the simulation results of the eight-machine 36-node test system and Hebei southern power grid show that the proposed low frequency oscillation online evaluation method has the features of high evaluation accuracy, fast evaluation speed, low error rate of unstable sample evaluation, and strong anti-noise ability.
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CHEN, CHUAN-SHOW. "BIOMECHANICAL STUDY ON A NEW TRAINING MACHINE AND METHOD FOR POWER AND STRENGTH." Journal of Mechanics in Medicine and Biology 05, no. 02 (June 2005): 243–51. http://dx.doi.org/10.1142/s0219519405001448.
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Strength and power are important in sports competition, and increasing ability of explosive muscle contraction force is key to winning for sports performance in events like jumping or throwing. In this study, Passive Repeated Plyometric (PRP) training method and the machine were designed. This machine allow one to training for top gear power with high frequency and without danger as compared with the conventional way of training like common way of plyomerics or using machine for isotonic muscle contraction. The PRP has it specific effects, which can be summarized as follow: 1. Motor driving PRP machine allow athlete training with high frequency, up to 300 rpm (0.2 Hz), especially for lower extremities to increase thrust force and force of body trunk. 2. PRP training method bring about the stretching reflex and elastic energy to recruit into a powerful muscle contraction. 3. This training machine formed a natural and powerful muscle contraction by stretching and shortening in a cycle of contraction, which is called stretching-shortening cycle or SSC. 4. Well-documented evidence from both theoretical and practical were achieved in 1998 Bangkok Asian game and the following Pusan2002 applying to track & field and basketball players.
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YANG, QINGHAI, and KYUNG SUP KWAK. "OPTIMAL TRAINING DESIGN FOR MIMO–OFDM SYSTEMS UNDER SPATIALLY CORRELATED DOUBLY SELECTIVE FADING CHANNELS." Journal of Circuits, Systems and Computers 16, no. 05 (October 2007): 673–97. http://dx.doi.org/10.1142/s0218126607003988.
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In this paper, we design an optimal training scheme for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems under spatially correlated time- and frequency- (doubly) selective fading channels. We first develop the optimal pilot symbols and placement of pilot clusters with respect to the minimum mean square error (MMSE) of the linear channel estimate. We then derive the optimal power allocation for pilot symbols in a two-water-level way: by maximizing the averaged capacity lower bound, how much power to be allocated for training is determined subject to the global water level (or the constraint of total transmit power); subsequently, pouring power to the pilot symbols with an approximately optimal water-filling scheme subject to the local water level (or the constraint of assigned power for training). In addition, for a particular OFDM size, the optimal number of pilot clusters is derived by maximizing the capacity lower bound and by minimizing the channel estimate's MMSE.
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Shubina, O. S., M. Ye Melnikov, and I. A. Veretelnikov. "Investigation of alpha-wave frequency characteristics in the patients with chronic tension headache and its modification during electromyographic-temperature training." Bulletin of Siberian Medicine 9, no. 2 (April 28, 2010): 42–46. http://dx.doi.org/10.20538/1682-0363-2010-2-42-46.
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Chronic tension headache is the most commonly experienced headache. Low effectiveness of its treatment is connected with lack of understanding of this disorder pathogenensis. It was shown that electromyographic-temperature training provoked modification of alpha-wave power and frequency: power of alpha increased, frequency of maximal increased as well.
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Won, An Na, and An Na Won. "Study of Awareness on Power Failure Crisis Response Training and Cost Burden in the Residential Sector – in KOREA." Advanced Materials Research 955-959 (June 2014): 1850–53. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.1850.
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A survey was carried out on 2,250 households for the purpose of understanding the awareness about power failure crisis response training and intention to bear cost of power failure measure in the residential sector. Implications of this study are as follows. Common households showed low awareness about power failure crisis response training. Also, while intention for cost burden on power failure measures such as emergency power facility slightly increased with increasing frequency and time of power failure, households generally had weak intention to bear cost.
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Katsoulis, Konstantina, and Catherine E. Amara. "The Effects Of Power Training Frequency On Functional Performance In Healthy, Older, Untrained Women." Medicine & Science in Sports & Exercise 52, no. 7S (July 2020): 143. http://dx.doi.org/10.1249/01.mss.0000671656.12040.86.
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Busso, Thierry, Henri Benoit, Régis Bonnefoy, Léonard Feasson, and Jean-René Lacour. "Effects of training frequency on the dynamics of performance response to a single training bout." Journal of Applied Physiology 92, no. 2 (February 1, 2002): 572–80. http://dx.doi.org/10.1152/japplphysiol.00429.2001.
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The aim of this study was to analyze the effect of an increase in training frequency on exercise-induced fatigue by using a systems model with parameters free to vary over time. Six previously untrained subjects undertook a 15-wk training experiment composed of 1) an 8-wk training period with three sessions per week (low-frequency training), 2) 1 wk without training, 3) a 4-wk training period with five sessions per week [high frequency training (HFT)], and 4) 2 wk without training. The systems input ascribed to training loads was computed from interval exercises and expressed in arbitrary units. The systems output ascribed to performance was evaluated three times each week using maximal power sustained over 5 min. The time-varying parameters of the model were estimated by fitting modeled performances to the measured ones using a recursive least squares method. The variations over time in the model parameters showed an increase in magnitude and duration of fatigue induced by a single training bout. The time needed to recover performance after a training session increased from 0.9 ± 2.1 days at the end of low-frequency training to 3.6 ± 2.0 days at the end of HFT. The maximal gain in performance for a given training load decreased during HFT. This study showed that shortening recovery time between training sessions progressively yielded a more persistent fatigue induced by each training.
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Petrenko, Tatiana I., Olga M. Bazanova, and Muhamed K. Kabardov. "Prospects for Using Adaptive Biofeedback to Train Musicians." RUDN Journal of Psychology and Pedagogics 16, no. 4 (December 15, 2019): 495–516. http://dx.doi.org/10.22363/2313-1683-2019-16-4-495-516.
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The use of biofeedback (BFB) technology becomes relevant for professional training of musicians to achieve success in psychomotor function control. We compared two training approaches: 20-22 sessions of alpha-EEG/EMG biofeedback implication to increase the аlpha-2 power while reducing the tension of the forehead muscles and sham biofeedback training. Fifty student musicians (18-28 years old) were divided randomly by age, gender, performing specialty, and individual EEG alpha-peak frequency (IAPF) into two groups. Music performance, state anxiety, self-actualization, nonverbal creativity, coefficient of finger movement optimality (Ko) and the efficiency of the single training session (E1) were evaluated before and after for both types of courses. We calculated the change of the EEG power in the individually adjusted alpha-2 range in the Pz and the integrated EMG power of the surface muscles of the forehead in response to finger movement. Training with biofeedback improved music performance score, increased self-actualization, Ko, and E1 while reducing pre-stage anxiety. The students who received the sham biofeedback did not achieve such improvements. When using biofeedback, students with baseline low alpha-peak frequency (LF) showed a more significant increase in scores for music performance, Ko, and E1 than students with high alpha-peak frequency (HF). In LF students, the sessions without biofeedback did not change the studied parameters. In this pilot placebo-controlled study, we demonstrated that achieving success in the optimal musical performance training depends on the baseline genetically determined IAPF and feedback implication from the EEG alpha-2 power and forehead muscle tone.
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Xi, Xinyu, Dehong Li, Dongwen Chen, and Yong Li. "Application of frequency optimization neural network method on power line communication." E3S Web of Conferences 300 (2021): 01018. http://dx.doi.org/10.1051/e3sconf/202130001018.
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The quality of broadband power line carrier communication mainly depends on the carrier communication frequency. However, there is a lack of fast and effective optimal carrier frequency selection method. One frequency selection method based on frequency point optimization neural network is proposed by this paper. This method combines transmission line theory and voltage partial reflection theory to build a power line carrier channel mathematical model of the distribution network. The input frequency point sample set is used as the training set of the frequency point optimization neural network to obtain a neural network model that can predict the local optimal frequency point set. Then the actual distribution network is taken as an example for simulation analysis. When inputting any frequency range, the model outputs the corresponding optimal frequency point set. Simulation results show that the algorithm saves a lot of input impedance or channel strength testing time, while the error rate is limited to about 3%.
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Rohleva, Mariana. "Exploring the Relationship between Endurance and Strength Training in Power Sports." Journal of Education and Training Studies 5, no. 4 (March 20, 2017): 204. http://dx.doi.org/10.11114/jets.v5i4.2292.
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The purpose of this research work is to track down the level of relation between strength and endurance in training exercises of handball athletes. The most successful ratio has been established during work with two groups of 10 players each, all of whom are university students. They were trained, respectively, according to the general training methodology, on the one hand, and a programme, developed by us, on the other.The object of our research is the effectiveness of the different in volume and intensity training work over the level of the identified physical qualities - strength and endurance. The groups are tested at the beginning and at the end of a two-month experimental period, during which 24 training sessions have been performed with the application of:1. A control run test - 4 km distance - at individual intensity of 85% and a pulse frequency of 145-155 b/min. The intensity is calculated on the basis of the best result, accomplished by the player. The pulse frequency is measured with a field micro-coordinator Seka, Sportronic - 250 and an analytical record, TYP, 2D, Syntron, Seka Software, Version 1.3, England.2. A strength test consisting of 5 sessions of eight repeats - semi-squats with bar - 40% of the maximum individual capability for 35 seconds.It has been established that the combination between workouts for strength and ednurance in a ratio of 2:1 respectively, gives a positive influence on both qualities. A training focused on endurance has a less significant effect on the strength of the athlete, and reversely, strength has a greater effect on endurance. It is recommended that in power sports the relative element of endurance in training not exceed 25-30%, and in sports with endurance as a leading quality - training for strength be in the margin of 20-30%.
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Cherapkina, L. P. "The cortical and extra-cortical bioelectrical processes determining the neurobiofeedback success and efficiency of sportsmen." Bulletin of Siberian Medicine 9, no. 2 (April 28, 2010): 78–82. http://dx.doi.org/10.20538/1682-0363-2010-2-78-82.
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The changes of the functional condition of the 35 highly qualified sportsmen, neurodynamic and its changes of the frequency characteristic of the heart rate in the background recording during open and closed eyes before and after 15-days neurobiofeedback course is analyzed. It is discovered, that the functional left hemisphere asymmetry was typical for sportsmen having the quiet wakefulness condition according the power of all main rhythms of the EEG. It is defined, that the predictor of the training efficiency is the theta-rhythm power in the recording during open eyes. The VLF-wave and the HF-wave middle power of the heart rate frequency and probably the hormonal cycle of women body have the material effect to training success.
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Evetovich, Tammy K., Terry J. Housh, Joseph P. Weir, Dona J. Housh, Glen O. Johnson, Kyle T. Ebersole, and Douglas B. Smith. "The effect of leg extension training on the mean power frequency of the mechanomyographic signal." Muscle & Nerve 23, no. 6 (June 2000): 973–75. http://dx.doi.org/10.1002/(sici)1097-4598(200006)23:6<973::aid-mus21>3.0.co;2-c.
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Tomíčková, Jitka, Jiří Jančík, Petr Dobšák, Jarmila Siegelová, and Roman Panovský. "Vliv kombinovaného vytrvalostního/silového tréninku na variabilitu srdeční frekvence u mužů s chronickou ischemickou chorobou srdeční." Studia sportiva 4, no. 1 (July 7, 2010): 5–11. http://dx.doi.org/10.5817/sts2010-1-1.
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31 men with chronic coronary artery disease (mean age 64 ± 11 years, mean body weight 83 ± 10 kg, mean height 177 ± 6 cm, mean ejection fraction of left heart ventricle 47 ± 11%), were examined before and aft er three months lasting aerobic training combined (from 3rd week) with strength training. Symptom-limited spiroergometry was provided before and aft er the training period. Th e training (exercise unit) was performed three times a week. Before exercise testing, short-term heart rate variability (HRV) analyses of all subjects were obtained. Frequency domain HRV indexes were determined in the morning during quiet periods under metronome controlled breathing. Total power (TP), low-frequency spectral component HRV (LF, 0,05–0,15 Hz), high-frequency spectral component HRV (HF, 0,15–0,5 Hz) and lowfrequency-to-high frequency (LF/HF) ratio were measured for 5 minutes in the monitoring. Twelve weeks lasting combined endurance/strength training increased HRV (HF, LF and TP) in men with stable chronic coronary disease .
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SARBAZ, YASHAR, FARZAD TOWHIDKHAH, SHAHRIAR GHARIBZADEH, and AYYOOB JAFARI. "GAIT SPECTRAL ANALYSIS: AN EASY FAST QUANTITATIVE METHOD FOR DIAGNOSING PARKINSON'S DISEASE." Journal of Mechanics in Medicine and Biology 12, no. 03 (June 2012): 1250041. http://dx.doi.org/10.1142/s0219519411004691.
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At present, there is no quantitative test to definitely diagnose Parkinson's disease (PD). For this purpose, we computed the power spectra of stride and swing signals of normal persons and patients. The evaluation of power spectra in stride on normal group shows that the main peak of the frequency range is in the range of 0.018 to 0.02 Hz. In contrast, the main peak frequency is different in different PD patients. Our studies on swing signal and its power spectra show that there is a significant difference between the amplitude of frequency components between normal and PD groups. Patients show power spectra amplitude even more than 10 times that of normal patients. The clinical data were obtained from http://www.physionet.org. For measuring time intervals, force sensors were used in the plantar portion of the foot. Power spectra of left stride, right stride, and left swing were computed. Frequency domain of power spectra was divided into 10 parts and then the surface area under each part was calculated. We used artificial neural network for classification of these groups. The clinical data was divided into two parts, training and test sets. An accuracy of 93.75% was obtained during training. The test data was used for validation of the classifier and an accuracy of 92.86% was obtained. The proposed classifier may be used as a tool for helping the clinicians to diagnose PD. Surely the final diagnosis should be obtained by an expert neurologist.
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Janczarek, Iwona, Witold Kędzierski, Anna Stachurska, Izabela Wilk, Ryszard Kolstrung, and Katarzyna Strzelec. "Autonomic nervous system activity in purebred Arabian horses evaluated according to the low frequency and high frequency spectrum versus racing performance." Acta Veterinaria Brno 85, no. 4 (2016): 355–62. http://dx.doi.org/10.2754/avb201685040355.
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Emotional excitability influences horses’ performance in sports and races. The aim of the study was to analyse whether the balance of the autonomic system which can occur when sympathetic system activity is at various levels might impact the horses’ racing performance. The study was carried out on 67 purebred Arabian horses trained for racing. The following indices were analysed: low frequency (LF), high frequency (HF), and the ratio of spectrum power at low frequencies to high frequencies (LF/HF). The autonomic nervous system activity was measured × 3 during the training season, at three-month intervals. Each examination included a 30-min measurement at rest and after a training session. The racing performance indices in these horses were also analysed. Better racing results were found in horses with enhanced LF/HF. The worst racing results were determined in horses with low LF.
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Kucharski, Tomasz. "Frequency Response Spectra Applied to Assess Efficiency of the Training Techniques." Key Engineering Materials 597 (December 2013): 137–44. http://dx.doi.org/10.4028/www.scientific.net/kem.597.137.
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The purpose of the research is to assess the increase of the muscle strength and power. Movement of the human body when the moving one impacts a stationary or moving body is taken under consideration. The waveform produced by an impact is transformed into frequency domain. The acceleration record is transformed as a complex spectrum, by the use of a Discrete Fourier Transformation. In this paper the applications of the discrete Fourier transform is discussed and it was pointed out that it can be fruitfully applied to analyze movement techniques during competition or training exercises. The acceleration response spectrum contains knowledge about efficiency of certain techniques. It has distinct features which can show that the energy is concentrated around several discrete frequencies. Data from the shape of a frequency response spectra curve can provide the coach and the performer with valuable information on technique and also give information on recommendations with respect to corrections and adjustments that can lead to performance enhancement. In this paper, the technique of a database creation is proposed what allows us to establish a particular set of circumstances under a specified protocol to observe and evaluate the implications of the resulting observations.
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Hertzog, Maxime, Michael C. Rumpf, and Karim Hader. "Resistance Training Status and Effectiveness of Low-Frequency Resistance Training on Upper-Body Strength and Power in Highly Trained Soccer Players." Journal of Strength and Conditioning Research 34, no. 4 (April 2020): 1032–39. http://dx.doi.org/10.1519/jsc.0000000000002202.
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Kessinger, Theodore Kent, Bridget Melton, Theresa Miyashita, and Greg Ryan. "The Effectiveness of Frequency-Based Resistance Training Protocols on Muscular Performance and Hypertrophy in Trained Males: A Critically Appraised Topic." Journal of Sport Rehabilitation 29, no. 7 (September 1, 2020): 1024–31. http://dx.doi.org/10.1123/jsr.2019-0491.
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Clinical Scenario: Manipulation of exercise variables in resistance training (RT) is an important component in the development of muscular strength, power, and hypertrophy. Currently, most research centers on untrained or recreationally trained subjects. This critically appraised topic focuses on studies that center on the well-trained subject with regard to frequency of training. Clinical Question: In well-trained male subjects, is there an association between RT frequency and the development of muscular strength and hypertrophy? Summary of Key Findings: Four studies met the inclusion criteria and were included for analysis. All studies showed that lower-frequency training could elicit muscular strength and hypertrophy increases. One study suggested that a higher frequency compared with a lower frequency may provide a slight benefit to hypertrophic development. One study reported a greater level of delayed onset muscle soreness with lower frequency training. The 4 studies demonstrate support for the clinical question. Clinical Bottom Line: Current evidence suggests that lower-frequency RT produces equal to greater improvements on muscular strength and hypertrophy in comparison to higher-frequency RT when volume is equated. The evidence is particularly convincing when lower-frequency RT is associated with a total-body training protocol in well-trained male subjects. Strength of Recommendation: There is moderate-to-strong evidence to suggest that lower-frequency RT, when volume is equated, will produce equal to greater improvements on muscular strength and hypertrophy in comparison to higher-frequency RT.
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Bazanova, O. M., D. Vernon, K. B. Muravlyova, and M. V. Skoraya. "INFLUENCE OF ALPHAEEG/EMG BIOFEEDBACK AND SELF-REGULATION PSYCHO TECHNIQUES ON THE HEART RATE VARIABILITY INDICES." Bulletin of Siberian Medicine 12, no. 2 (April 28, 2013): 43–51. http://dx.doi.org/10.20538/1682-0363-2013-2-43-51.
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With the purpose to study the impact of the upper frequency alpha EEG power increasing neurofeedback training (ANFT) on the cognitive performance, EEG alpha-activity and heart rate variability (HRV) 27 healthy men aged 18–34 years in pre, post and follow up one month 10 sessions ANFT time were investigated. The AFNT enhanced the fluency in cognitive performance, alpha frequency and power in upper frequency range and HRV only in participants with low baseline alpha frequency. While mock AFNT did change neither cognitive performance, nor alpha-activity, nor HRV indices. ANT reduces activation in cognitive load, and this effect persists for a month.
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Soyal, Mehmet, and Nuri M. Çelik. "Comparing the hand grip power and creatine kinase levels of U-17 judo national team athletes before and after a 6-week strength training." Pedagogy of Physical Culture and Sports 24, no. 4 (August 30, 2020): 163–68. http://dx.doi.org/10.15561/26649837.2020.0402.
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Background and Study Aim. The aim of this study is to compare the hand grip power and creatine kinase levels of male and female U-17 National Team Athletes before and after a 6-week strength training.
Material and Methods. 15 female and 15 male U-17 athletes, who previously participated in international competitions, participated in our study. Besides the hand grip power and creatine kinase values, age, height, weight, and BMI (body mass index) values of the athletes were measured before and after the training. As the conclusion of the measurements, the mean age of the female participant athletes was determined as 14,93 years, their mean height was 158,3 cm, and the mean age of the male athletes was 15,73 years, while their mean height was 173,1 cm.
Results: As the conclusion of the measurements, it was determined that there were statistically significant differences between the right hand grip power and left hand grip power parameters of male and female participant athletes measured before and after the 6-week training. Moreover, it was determined that there were statistically significant differences between the pre-test and post-test measurements of creatine kinase values of both male and female athletes (p> 0,05).
Conclusions. As the conclusion, it was determined that the 6-week strength trainings applied to U-17 Judo National Team athletes caused significant changes in their hand grip power and creatine kinase values. The significant results obtained from our study are considered to be originated from the duration, scope, frequency, severity, and content of the training.
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Hickson, R. C., C. Foster, M. L. Pollock, T. M. Galassi, and S. Rich. "Reduced training intensities and loss of aerobic power, endurance, and cardiac growth." Journal of Applied Physiology 58, no. 2 (February 1, 1985): 492–99. http://dx.doi.org/10.1152/jappl.1985.58.2.492.
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Twelve subjects participated in an exercise program of cycling and running 40 min/day, 6 days/wk. After 10 wk, they continued to train with either a one-third or two-thirds reduction in work rates for an additional 15 wk. Frequency and duration for the additional training remained the same as during the 10 wk of training. The average increases in maximum O2 uptake (VO2 max) were between 11 and 20% when measured during cycling and treadmill running after 10 wk of training. VO2 max was not maintained at the 6-day/wk training levels with a one-third reduction in training intensity but was still higher than pretraining levels. With a two-thirds reduction in intensity, VO2 max declined to an even greater extent than with the one-third reduction. Short-term endurance (approximately 5 min) was maintained in the one-third reduced group but was markedly reduced in the two-thirds reduced group. Long-term endurance was decreased significantly from training by 21% in the one-third reduced group (184–145 min) and by 30% in the two-thirds reduced group (202–141 min). Calculated left ventricular mass, obtained from echocardiographic measurements, increased approximately 15% after training but returned to control levels after reduced training in both groups. These results demonstrate that training intensity is an essential requirement for maintaining the increased aerobic power and cardiac enlargement with reduced training.
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Stavrinou, Pinelopi, Gregory Bogdanis, Christoforos Giannaki, Gerasimos Terzis, and Marios Hadjicharalambous. "High-intensity Interval Training Frequency: Cardiometabolic Effects and Quality of Life." International Journal of Sports Medicine 39, no. 03 (February 2018): 210–17. http://dx.doi.org/10.1055/s-0043-125074.
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AbstractThe effects of high intensity interval training (HIIT) frequency on cardiometabolic health and quality of life were examined in 35 healthy inactive adults (age: 31.7±2.6 yrs, VO2peak: 32.7±7.4 ml·kg−1 ·min−1). Participants were randomly assigned to a control (CON) and two training groups, which performed 10×60-s cycling at ~83% of peak power, two (HIIT-2) or three times per week (HIIT-3) for eight weeks. Compared with CON, both training regimes resulted in similar improvements in VO2peak (HIIT-2: 10.8%, p=0.048, HIIT-3: 13.6%, p=0.017), waist circumference (HIIT-2: -1.4 cm, p=0.048, HIIT-3: -2.4 cm, p=0.028), thigh cross-sectional area (HIIT-2: 11.4 cm2, p=0.001, HIIT-3: 9.3 cm2, p=0.001) and the physical health component of quality of life (HIIT-2: 8.4, p=0.001, HIIT-3: 12.2, p=0.001). However, HIIT-3 conferred additional health-related benefits by reducing total body and trunk fat percentage (p<0.05, compared with CON), total cholesterol and low-density lipoprotein-cholesterol (p<0.02, compared with CON) and by improving the mental component of quality of life (p=0.045, compared with CON). In conclusion, performing HIIT only twice per week is effective in promoting cardiometabolic health-related adaptations and quality of life in inactive adults. However, higher HIIT frequency is required for an effect on fat deposits, cholesterol and mental component of well-being.
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Dokht Shakibjoo, Ali, Mohammad Moradzadeh, Seyed Zeinolabedin Moussavi, and Lieven Vandevelde. "A Novel Technique for Load Frequency Control of Multi-Area Power Systems." Energies 13, no. 9 (April 25, 2020): 2125. http://dx.doi.org/10.3390/en13092125.
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In this paper, an adaptive type-2 fuzzy controller is proposed to control the load frequency of a two-area power system based on descending gradient training and error back-propagation. The dynamics of the system are completely uncertain. The multilayer perceptron (MLP) artificial neural network structure is used to extract Jacobian and estimate the system model, and then, the estimated model is applied to the controller, online. A proportional–derivative (PD) controller is added to the type-2 fuzzy controller, which increases the stability and robustness of the system against disturbances. The adaptation, being real-time and independency of the system parameters are new features of the proposed controller. Carrying out simulations on New England 39-bus power system, the performance of the proposed controller is compared with the conventional PI, PID and internal model control based on PID (IMC-PID) controllers. Simulation results indicate that our proposed controller method outperforms the conventional controllers in terms of transient response and stability.
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Chauvière, L., and W. Singer. "Neurofeedback Training of Gamma Oscillations in Monkey Primary Visual Cortex." Cerebral Cortex 29, no. 11 (February 23, 2019): 4785–802. http://dx.doi.org/10.1093/cercor/bhz013.
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Abstract In humans, neurofeedback (NFB) training has been used extensively and successfully to manipulate brain activity. Feedback signals were derived from EEG, fMRI, MEG, and intracranial recordings and modifications were obtained of the BOLD signal, of the power of oscillatory activity in distinct frequency bands and of single unit activity. The purpose of the present study was to examine whether neuronal activity could also be controlled by NFB in early sensory cortices whose activity is thought to be influenced mainly by sensory input rather than volitional control. We trained 2 macaque monkeys to enhance narrow band gamma oscillations in the primary visual cortex by providing them with an acoustic signal that reflected the power of gamma oscillations in a preselected band and rewarding increases of the feedback signal. Oscillations were assessed from local field potentials recorded with chronically implanted microelectrodes. Both monkeys succeeded to raise gamma activity in the absence of visual stimulation in the selected frequency band and at the site from which the NFB signal was derived. This suggests that top–down signals are not confined to just modulate stimulus induced responses but can actually drive or facilitate the gamma generating microcircuits even in a primary sensory area.
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Ratajczak, Ewa, Marcin Hajnowski, Mateusz Stawicki, and Włodzisław Duch. "Novel Methodological Tools for Behavioral Interventions: The Case of HRV-Biofeedback. Sham Control and Quantitative Physiology-Based Assessment of Training Quality and Fidelity." Sensors 21, no. 11 (May 25, 2021): 3670. http://dx.doi.org/10.3390/s21113670.
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Scientific research on heart rate variability (HRV) biofeedback is burdened by certain methodological issues, such as lack of consistent training quality and fidelity assessment or control conditions that would mimic the intervention. In the present study, a novel sham HRV-biofeedback training was proposed as a credible control condition, indistinguishable from the real training. The Yield Efficiency of Training Index (YETI), a quantitative measure based on the spectral distribution of heart rate during training, was suggested for training quality assessment. A training fidelity criterion derived from a two-step classification process based on the average YETI index and its standard deviation (YETISD) was suggested. We divided 57 young, healthy volunteers into two groups, each subjected to 20 sessions of either real or sham HRV-biofeedback. Five standard HRV measures (standard deviation of the NN (SDNN), root mean square of the standard deviation of the NN (RMSSD), total power, low-frequency (LF), and high-frequency (HF) power) collected at baseline, after 10 and 20 sessions were subjected to analysis of variance. Application of a training fidelity criterion improved sample homogeneity, resulting in a substantial gain in effect sizes of the group and training interactions for all considered HRV indices. Application of methodological amendments, including proper control conditions (such as sham training) and quantitative assessment of training quality and fidelity, substantially improves the analysis of training effects. Although presented on the example of HRV-biofeedback, this approach should similarly benefit other behavioral training procedures that interact with any of the many psychophysiological mechanisms in the human body.
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Chien, Ting-Hsuan, Yu-Chuan Huang, and Yuan-Yih Hsu. "Neural Network-Based Supplementary Frequency Controller for a DFIG Wind Farm." Energies 13, no. 20 (October 13, 2020): 5320. http://dx.doi.org/10.3390/en13205320.
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An artificial neural network (ANN)-based supplementary frequency controller is designed for a doubly fed induction generator (DFIG) wind farm in a local power system. Since the optimal controller gain that gives highest the frequency nadir or lowest peak frequency is a complicated nonlinear function of load disturbance and system variables, it is not easy to use analytical methods to derive the optimal gain. The optimal gain can be reached through an exhaustive search method. However, the exhaustive search method is not suitable for online applications, since it takes a long time to perform a great number of simulations. In this work, an ANN that uses load disturbance, wind penetration, and wind speed as the inputs and the desired controller gain as the output is proposed. Once trained by a proper set of training patterns, the ANN can be employed to yield the desired gain in a very efficient manner, even when the operating condition is not included in the training set. Therefore, the proposed ANN-based controller can be used for real-time frequency control. Results from MATLAB/SIMULINK simulations performed on a local power system in Taiwan reveal that the proposed ANN can yield a better frequency response than the fixed-gain controller.
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Smolyakov, Yuriy N., Boris I. Kuznik, Ekaterina S. Guseva, and Sergey O. Davydov. "Heart rate variability in women with essential hypertension under exposure of regular moderate physical training." Systemic Hypertension 16, no. 4 (December 15, 2019): 61–64. http://dx.doi.org/10.26442/2075082x.2019.4.190636.
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The task of the study was to elucidate the effect of moderate exercise on heart rate variability (HRV) in women who regularly take kinesitherapy courses. Materials and methods. Studies were conducted on 72 women with essential hypertension (EH), divided into 2 subgroups: first (EH-1) included 37 women suffering from stage II EH and under medical therapy, the second (EH-2) consisted of patients who underwent along with medication treatment, regular courses of kinesitherapy. To evaluate the characteristics of HRV, a photoplethysmography method was used. The following indicators were used: SDRR is the standard deviation of all cardiointervals, RMSSD is the square root of the average sum of squares of cardiointerval differences, LF - is the oscillation power in the low frequency range, due to the activity of the sympathetic section, HF - is the power in the high frequency range, associated with respiratory movements and caused by vagal activity, LF/HF - is the power ratio, reflecting sympathetic balance, CVI - nonlinear parasympathetic index, CSI - nonlinear sympathetic index. Results. It was established that the average heart rate in women of both groups is approximately the same, while all other indicators (with the exception of LF/HF and CSI) were significantly higher in patients EH-2 group. In patients EH-2 group, there is a significantly larger value of SDRR, RMSSD, LF, HF. In the frequency analysis, no increase in the total power of cardiointerval oscillations and autonomic balance (LF/HF) was detected. A pronounced increase in the nonlinear parasympathetic index (CVI) has been shown, while the sympathetic index (CSI) remained unchanged. Conclusion. Regular use of kinesitherapy courses helps to increase the tone of the parasympathetic division of the autonomic nervous system, which is significantly depressed in EH.
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Gambassi, Bruno Bavaresco, Hélio José Coelho-Junior, Paulo Adriano Schwingel, Fabiano de Jesus Furtado Almeida, Tânia Maria Gaspar Novais, Paula de Lourdes Lauande Oliveira, Bismarck Ascar Sauaia, Cristiane Dominice Melo, Marco Carlos Uchida, and Bruno Rodrigues. "Resistance Training and Stroke: A Critical Analysis of Different Training Programs." Stroke Research and Treatment 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/4830265.
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The aim of this study was to carry out a literature review on the overall benefits of resistance training (RT) after stroke and undertake a critical analysis of the resistance exercise programs surveyed (rest interval between sets and exercises, number of sets, number of repetitions, intensity, duration of training, and weekly frequency). To obtain articles for the review, we searched PubMed, Google Scholar, and Physiotherapy Evidence Database (PEDro). Inclusion criteria were considered using the PICO (population, intervention, control/comparison, and outcome variables) model. The following characteristics were recorded for all articles: type of study, author, year of publication, participants (time after stroke, sample size, and age), benefits of RT, and structured resistance exercise programs. Positive effects of training were found on anxiety status, quality of life, muscle hypertrophy, cognitive function, strength, and muscle power. Only 5 studies described the main variables of RT in detail. Lack of control of some variables of RT may negatively affect the results of this practice. The findings of the present study may further inform health and physical conditioning professionals on the importance and necessity of using the main variables in the search for benefits for individuals with stroke.
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Walker, Jonathan E. "Power Spectral Frequency and Coherence Abnormalities in Patients with Intractable Epilepsy and Their Usefulness in Long-Term Remediation of Seizures Using Neurofeedback." Clinical EEG and Neuroscience 39, no. 4 (October 2008): 203–5. http://dx.doi.org/10.1177/155005940803900410.
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Medically intractable seizures appear to be highly correlated with focal slow activity (delta or theta). They also correlate highly with decreases in the coherence of theta. Normalization of focal slowing and of decreased theta coherence will probably be the neurofeedback approaches most likely to decrease or eliminate seizures in future cases. Neurofeedback has been used for over 35 years to reduce the incidence and severity of seizures. With power training to decrease theta and increase the sensorimotor rhythm (12–15 Hz), an average of 82% of patients experienced a significant reduction in seizure frequency, and occasional remissions were seen. Recent improvements using QEEG to guide neurofeedback training have made it possible to eliminate seizures in most patients, even those with intractable seizures. Following our previous study in 2005, we report an additional 25 patients so treated. We also report an analysis of the frequency of QEEG abnormalities in this patient group. All of the intractable epileptic patients had one or more slow foci (excessive theta or delta compared with the normal database). One third had a relative deficiency of beta power. One fourth had a deficiency of absolute delta. Eighteen percent had excessive absolute alpha power, 18% had deficient absolute alpha power, 18% percent had excessive absolute beta power, and 18% percent had deficient absolute beta power. Hypocoherence of theta was found in 75%, and decreases in alpha coherence were noted in 42%. Hypocoherence of beta was found in 50%, and hypocoherence of delta was found in 25%. Increases in alpha coherence were noted in 33%. Seventeen percent had no coherence abnormalities. When most of the power and coherence abnormalities were normalized with neurofeedback training, all the patients became seizure-free; 76% no longer required an anticonvulsant for seizure control.
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Zhao, Zhenyu, Chuan Wu, and Qing Zhou. "A Self-Powered Basketball Training Sensor Based on Triboelectric Nanogenerator." Applied Sciences 11, no. 8 (April 14, 2021): 3506. http://dx.doi.org/10.3390/app11083506.
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During the basketball training for beginner children, sensors are needed to count the number of times the basketball hits the target area in a certain period of time to evaluate the training effect. This study proposes a self-powered basketball training sensor, based on a triboelectric nanogenerator. The designed sensor with a rectangular floor shape will output a pulse signal with the same frequency as the basketball impact to achieve the measurement function through the mutual contact of the internal copper (Cu) and polytetrafluoroethylene (PTFE). Test results show that the working frequency of the sensor is 0 to 5 Hz, the working environment temperature should be less than 75 °C, the working environment humidity should be less than 95%, and which has high reliability. Further tests show that the maximum output voltage, current, and power of the sensor can reach about 52 V, 4 uA, and 26.5 uW with a 10 MΩ resistance in series, respectively, and the output power can light up 12 light-emitting diode (LED) lights in real-time. Compared with the traditional statistical method of manual observation, the sensor can automatically count data in a self-powered manner, and also can light up the LED lights in real-time as an indicator of whether the basketball impacts the target area, to remind beginner children in real-time.
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Hautala, Arto J., Timo H. Mäkikallio, Antti Kiviniemi, Raija T. Laukkanen, Seppo Nissilä, Heikki V. Huikuri, and Mikko P. Tulppo. "Cardiovascular autonomic function correlates with the response to aerobic training in healthy sedentary subjects." American Journal of Physiology-Heart and Circulatory Physiology 285, no. 4 (October 2003): H1747—H1752. http://dx.doi.org/10.1152/ajpheart.00202.2003.
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Individual responses to aerobic training vary from almost none to a 40% increase in aerobic fitness in sedentary subjects. The reasons for these differences in the training response are not well known. We hypothesized that baseline cardiovascular autonomic function may influence the training response. The study population included sedentary male subjects ( n = 39, 35 ± 9 yr). The training period was 8 wk, including 6 sessions/wk at an intensity of 70–80% of the maximum heart rate for 30–60 min/session. Cardiovascular autonomic function was assessed by measuring the power spectral indexes of heart rate variability from 24-h R-R interval recordings before the training period. Mean peak O2 uptake increased by 11 ± 5% during the training period (range 2–19%). The training response correlated with age ( r = –0.39, P = 0.007) and with the values of the high-frequency (HF) spectral component of R-R intervals (HF power) analyzed over the 24-h recording ( r = 0.46, P = 0.002) or separately during the daytime hours ( r = 0.35, P = 0.028) and most strongly during the nighttime hours ( r = 0.52, P = 0.001). After adjustment for age, HF power was still associated with the training response (e.g., P = 0.001 analyzed during nighttime hours). These data show that cardiovascular autonomic function is an important determinant of the response to aerobic training among sedentary men. High vagal activity at baseline is associated with the improvement in aerobic power caused by aerobic exercise training in healthy sedentary subjects.
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Petrescu, Tomina Dana, and Dragoș Ionescu Bondoc. "Method and the machine for training the running speed." Annals of "Dunarea de Jos" University of Galati Fascicle XV Physical Education and Sport Management 2 (November 26, 2019): 40–42. http://dx.doi.org/10.35219/efms.2019.2.09.
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Former sprint runner, I was particularly concerned with sprint training methodology. In this regard, I have experimented together with our training colleagues, an exercise that stimulates the increase of speed of the steps in speed running, using an installation made by our own coach, designed to stimulate and increase the frequency of the steps, coaching the so-called "super-speed”. In order to increase the running speed, besides developing motor skills, a series of technical objectives must be achieved through training.It is known that using run-on exercises, similar to running on a downhill slope, there is a series of positive influences on the kinetics of the running speed of which the impulse angle and the orientation of the impulse vector in the CGM on - the impulse angle is primordial, along with:-achieving the optimum ratio between the frequency and the length of the steps;-increasing the power released by the impulse foot;-decreasing the impulse angle;-increasing the frequency of the treadmills achieved per unit of time;-increasing the length of the steps.Our experiment has attempted to justify this kind of exercise in speed training. Finally, it was found that this exercise positively affects the last two goals listed above.
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Sadowski, Jerzy, Andrzej Mastalerz, Wilhelm Gromisz, and Tomasz Niźnikowski. "Effectiveness of the Power Dry-Land Training Programmes in Youth Swimmers." Journal of Human Kinetics 32, no. 1 (May 1, 2012): 77–86. http://dx.doi.org/10.2478/v10078-012-0025-5.
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Effectiveness of the Power Dry-Land Training Programmes in Youth Swimmers The aim of the study was to evaluate the effects of the dry-land power training on swimming force, swimming performance and strength in youth swimmers. Twenty six male swimmers, free from injuries and training regularly at least 6 times a week, were enrolled in the study and randomly assigned to one of two groups: experimental (n=14, mean age 14.0 ± 0.5 yrs, mean height 1.67±0.08 m and mean body mass 55.71 ±9.55 kg) and control (n=12, mean age 14.1 ± 0.5 yrs, mean height 1.61±0.11 m and mean body mass 49.07 ±8.25 kg). The experimental group took part in a combined swimming and dry-land power training. The control group took part in swimming training only. The training programmes in water included a dominant aerobic work in front crawl. In this research the experimental group tended to present slightly greater improvements in sprint performance. However, the stroke frequency insignificantly decreased (-4.30%, p>0.05) in the experimental group and increased (6.28%, p>0.05) in the control group. The distance per stroke insignificantly increased in the experimental group (5.98%, p>0.05) and insignificantly decreased in the control group (-5.36%, p>0.05). A significant improvement of tethered swimming force for the experimental group (9.64%, p<0.02) was found, whereas the increase was not statistically significant in the control group (2.86%, p>0.05). The main data cannot clearly state that power training allowed an enhancement in swimming performance, although a tendency to improve swimming performance in tethered swimming was noticed.
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Bossi, Arthur H., Cristian Mesquida, Louis Passfield, Bent R. Rønnestad, and James G. Hopker. "Optimizing Interval Training Through Power-Output Variation Within the Work Intervals." International Journal of Sports Physiology and Performance 15, no. 7 (August 1, 2020): 982–89. http://dx.doi.org/10.1123/ijspp.2019-0260.
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Purpose: Maximal oxygen uptake () is a key determinant of endurance performance. Therefore, devising high-intensity interval training (HIIT) that maximizes stress of the oxygen-transport and -utilization systems may be important to stimulate further adaptation in athletes. The authors compared physiological and perceptual responses elicited by work intervals matched for duration and mean power output but differing in power-output distribution. Methods: Fourteen cyclists ( 69.2 [6.6] mL·kg−1·min−1) completed 3 laboratory visits for a performance assessment and 2 HIIT sessions using either varied-intensity or constant-intensity work intervals. Results: Cyclists spent more time at during HIIT with varied-intensity work intervals (410 [207] vs 286 [162] s, P = .02), but there were no differences between sessions in heart-rate- or perceptual-based training-load metrics (all P ≥ .1). When considering individual work intervals, minute ventilation () was higher in the varied-intensity mode (F = 8.42, P = .01), but not respiratory frequency, tidal volume, blood lactate concentration [La], ratings of perceived exertion, or cadence (all F ≤ 3.50, ≥ .08). Absolute changes (Δ) between HIIT sessions were calculated per work interval, and Δ total oxygen uptake was moderately associated with (r = .36, P = .002). Conclusions: In comparison with an HIIT session with constant-intensity work intervals, well-trained cyclists sustain higher fractions of when work intervals involved power-output variations. This effect is partially mediated by an increased oxygen cost of hyperpnea and not associated with a higher [La], perceived exertion, or training-load metrics.
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Pei, Guangying, Jinglong Wu, Duanduan Chen, Guoxin Guo, Shuozhen Liu, Mingxuan Hong, and Tianyi Yan. "Effects of an Integrated Neurofeedback System with Dry Electrodes: EEG Acquisition and Cognition Assessment." Sensors 18, no. 10 (October 11, 2018): 3396. http://dx.doi.org/10.3390/s18103396.
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Electroencephalogram (EEG) neurofeedback improves cognitive capacity and behaviors by regulating brain activity, which can lead to cognitive enhancement in healthy people and better rehabilitation in patients. The increased use of EEG neurofeedback highlights the urgent need to reduce the discomfort and preparation time and increase the stability and simplicity of the system’s operation. Based on brain-computer interface technology and a multithreading design, we describe a neurofeedback system with an integrated design that incorporates wearable, multichannel, dry electrode EEG acquisition equipment and cognitive function assessment. Then, we evaluated the effectiveness of the system in a single-blind control experiment in healthy people, who increased the alpha frequency band power in a neurofeedback protocol. We found that upregulation of the alpha power density improved working memory following short-term training (only five training sessions in a week), while the attention network regulation may be related to other frequency band activities, such as theta and beta. Our integrated system will be an effective neurofeedback training and cognitive function assessment system for personal and clinical use.
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Ghoshuni, Majid, Mohammad Firoozabadi, Mohammad Ali Khalilzadeh, and Mohammad Reza Hashemi Golpayegani. "THE EFFECT OF SENSORIMOTOR RHYTHM ENHANCING NEUROFEEDBACK ON POWER OF ADJACENT FREQUENCY BANDS." Biomedical Engineering: Applications, Basis and Communications 24, no. 04 (August 2012): 307–12. http://dx.doi.org/10.4015/s1016237212500238.
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Sensorimotor rhythm (SMR) neurofeedback training (NFT) has an important role in improvement of cognitive functions in both clinical and healthy individuals. It is very possible that in SMR NFT adjacent frequency bands, such as alpha and beta1, be affected by SMR enhancing neurofeedback. Therefore, the adjacent frequency bands, in addition to SMR, may be associated with the improvement of the cognitive functions. Eight sessions of NFT were applied to healthy individuals to enhance their SMR activity. In order to investigate the effect of SMR enhancing neurofeedback on the power of adjacent frequency bands, correlation between the change in SMR activity and the change in alpha or beta1 activity was computed. The results revealed that there is a highly significant positive correlation between the change in SMR and beta1 activities. The given outcome suggests that during SMR NFT, the effect of both SMR and beta1 be considered together on the improvement of the cognitive functions.
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Yu, Ying Xin, and Gang Wang. "A Novel Channel Estimation Method Based on Power-Delay Profile." Applied Mechanics and Materials 602-605 (August 2014): 2871–77. http://dx.doi.org/10.4028/www.scientific.net/amm.602-605.2871.
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Considering the physical layer specification of the IEEE802.11 protocol as background, a novel LSE (least square estimation) algorithm based on power-delay profile of wireless channel is proposed. In multi-path time-variant channel, receiver carries out a primary MMSE estimation using training symbols and pilots of OFDM symbol firstly. Then the channel impulse response is obtained from frequency response estimated by MMSE. Finally, LSE algorithm is applied to revise the channel impulse response according to the power-delay profile. The LSE algorithm can reduce the noise level of MMSE estimation in time-domain which is equivalent to increasing the SNR to the output of 2-D wiener filter. Simulation results confirm that the proposed LSE algorithm gains a better performance in contrast to MMSE algorithm. As the Doppler frequency shift increases, LSE outperforms more significantly than MMSE algorithm.
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Tønnessen, Espen, Vegard Rasdal, Ida S. Svendsen, Thomas A. Haugen, Erlend Hem, and Øyvind Sandbakk. "Concurrent Development of Endurance Capacity and Explosiveness: Training Characteristics of World-Class Nordic Combined Athletes." International Journal of Sports Physiology and Performance 11, no. 5 (July 2016): 643–51. http://dx.doi.org/10.1123/ijspp.2015-0309.
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Performing at an elite level in Nordic combined (NC) requires both the explosiveness required for ski jumping performance and the endurance capacity required for cross-country skiing.Purpose:To describe the characteristics of world-class NC athletes’ training and determine how endurance and non–endurance (ie, strength, power, and ski jumping) training is periodized.Methods:Annual training characteristics and the periodization of endurance and non–endurance training were determined by analyzing the training diaries of 6 world-class NC athletes.Results:Of 846 ± 72 annual training hours, 540 ± 37 h were endurance training, with 88.6% being low-, 5.9% moderate-, and 5.5% high-intensity training. While training frequency remained relatively constant, the total training volume was reduced from the general preparatory to the competition phase, primarily due to less low- and moderate-intensity training (P < .05). A total of 236 ± 55 h/y were spent as non–endurance training, including 211 ± 44 h of power and ski-jump-specific training (908 ± 165 ski jumps and ski-jump imitations). The proportion of non–endurance training increased significantly toward the competition phase (P < .05).Conclusion:World-class NC athletes reduce the volume of low- and moderate-intensity endurance training toward the competition phase, followed by an increase in the relative contribution of power and ski-jump training. These data provide novel insight on how successful athletes execute their training and may facilitate more-precise coaching of future athletes in this sport. In addition, this information is of high relevance for the training organization of other sports that require optimization of 2 fundamentally different physical capacities.
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Lee, Jihoon, Seungwook Yoon, and Euiseok Hwang. "Frequency Selective Auto-Encoder for Smart Meter Data Compression." Sensors 21, no. 4 (February 22, 2021): 1521. http://dx.doi.org/10.3390/s21041521.
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With the development of the internet of things (IoT), the power grid has become intelligent using massive IoT sensors, such as smart meters. Generally, installed smart meters can collect large amounts of data to improve grid visibility and situational awareness. However, the limited storage and communication capacities can restrain their infrastructure in the IoT environment. To alleviate these problems, efficient and various compression techniques are required. Deep learning-based compression techniques such as auto-encoders (AEs) have recently been deployed for this purpose. However, the compression performance of the existing models can be limited when the spectral properties of high-frequency sampled power data are widely varying over time. This paper proposes an AE compression model, based on a frequency selection method, which improves the reconstruction quality while maintaining the compression ratio (CR). For efficient data compression, the proposed method selectively applies customized compression models, depending on the spectral properties of the corresponding time windows. The framework of the proposed method involves two primary steps: (i) division of the power data into a series of time windows with specified spectral properties (high-frequency, medium-frequency, and low-frequency dominance) and (ii) separate training and selective application of the AE models, which prepares them for the power data compression that best suits the characteristics of each frequency. In simulations on the Dutch residential energy dataset, the frequency-selective AE model shows significantly higher reconstruction performance than the existing model with the same CR. In addition, the proposed model reduces the computational complexity involved in the analysis of the learning process.
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Wiratama, Gede Aditya. "DOUBLE LEG SPEED HOP AND HALF SQUAT JUMP IMPROVE LEG MUSCLE POWER." Sport and Fitness Journal 9, no. 2 (May 28, 2021): 139. http://dx.doi.org/10.24843/spj.2021.v09.i02.p07.
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Leg muscle explosiveness is one of the factors that determine the stability of jumping techniques in football. This research aims to prove that the combined training of Double Leg Speed ??Hop and Half Squat Jump is better than the Hurdle Jump in increasing leg muscle explosive power in male students participating in extracurricular football at SMP Negeri 2 Kuta Utara. Type of this research was true experimental with randomized pre and post-test with control group design. The research subjects were 18 male extracurricular football students at SMP Negeri 2 Kuta Utara which were divided into two different treatment groups. Treatment group was given training in a combination of Double Leg Speed ??Hop and Half Squat Jump and control group was given hurdles training, with a frequency of training 3 times a week for 6 weeks. Measurement of leg muscle strength measured using a meter board with a vertical jump test. The results of the study in both groups obtained the average leg muscle explosive power before training in the combination of Double Leg Speed ??Hop and Half Squat Jump 38.49 ± 4.658 cm, while after training the combination of Double Leg Speed ??Hop and Half Squat Jump became 48.17 ± 4.305 cm. The average explosive power of leg muscles before the Skipping Jump training was 36.63 ± 3.953 cm, while after the skipping jump training was 40.79 ± 4.227 cm. The mean difference test in the increased leg muscle power in treatment group and control group using independent t-tests in the post-test data of the two groups showed that p = 0.00 (p <0.05). It was concluded that the exercises in Treatment Group and Control Group both had an increased effect and in Treatment Group increased leg muscle power more than in Control Group. This research suggestions are expected to coaches can provide training properly and use evaluation monitoring improves athlete achievement.
Keywords: Leg Muscle Explosive Power; Double Leg Speed ??Hop; Half Squat Jump; Hurdles Jumping; Football Extracurricular Boys SMP N 2 Kuta Utara
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Su, Yang, Ming-Hui Liu, Xu-Hui Kong, Chen-Jun Guo, Jiang Zhu, Xiu-Ming Li, and Qu Zhou. "Evaluation of Breakdown Voltage and Water Content in Transformer Oil Using Multi Frequency Ultrasonic and Generalized Regression Neural Network." Journal of Nanoelectronics and Optoelectronics 16, no. 3 (March 1, 2021): 387–94. http://dx.doi.org/10.1166/jno.2021.2971.
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Power transformer is regarded as one of the crucial part of electrical power transmission and distribution system. The quality of transformer oil can directly affect the operation of the power transformer, and breakdown voltage (BDV) and water content are the two main parameters of transformer oil quality. Monitoring the BDV and water content of transformer oil is considered as an important method to evaluate the safe operation of power systems. This work proposes the measurement of BDV and water content in transformer oil using multi frequency ultrasonic and generalized regression neural network (GRNN). The BDV and water content of all 210 samples were firstly tested according to the traditional testing methods and the multi frequency ultra-sonic technology, separately. And then the 210 samples were randomly divided into training sets and test sets. The obtained multi frequency ultrasonic data were set as the input of GRNN, and the BDV and water content as the output of GRNN. Moreover, the 20-fold-cross-validation was incorporated to obtain the best smoothing factor δ for GRNN. Finally, the GRNN model was trained by the training sets with δ =4.54 and was evaluated with the test sets. All results show that the lower BDV or the higher water content of the sample will cause greater ultrasonic sound attenuation, and the prediction accuracy of the prediction model for BDV and water con-tent in oil is up to 95%. It provides a new method for evaluating the health of transformer oil.
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Nicolò, Andrea, Marco Montini, Michele Girardi, Francesco Felici, Ilenia Bazzucchi, and Massimo Sacchetti. "Respiratory Frequency as a Marker of Physical Effort During High-Intensity Interval Training in Soccer Players." International Journal of Sports Physiology and Performance 15, no. 1 (January 1, 2020): 73–80. http://dx.doi.org/10.1123/ijspp.2019-0028.
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Purpose: Variables currently used in soccer training monitoring fail to represent the physiological demand of the player during movements like accelerations, decelerations, and directional changes performed at high intensity. We tested the hypothesis that respiratory frequency (fR) is a marker of physical effort during soccer-related high-intensity exercise. Methods: A total of 12 male soccer players performed a preliminary intermittent incremental test and 2 shuttle-run high-intensity interval training (HIIT) protocols, in separate visits. The 2 HIIT protocols consisted of 12 repetitions over 9 minutes and differed in the work-to-recovery ratio (15:30 vs 30:15 s). Work rate was self-paced by participants to achieve the longest possible total distance in each HIIT protocol. Results: Work-phase average metabolic power was higher (P < .001) in the 15:30-second protocol (31.7 [3.0] W·kg−1) compared with the 30:15-second protocol (22.8 [2.0] W·kg−1). Unlike heart rate and oxygen uptake, fR showed a fast response to the work–recovery alternation during both HIIT protocols, resembling changes in metabolic power even at supramaximal intensities. Large correlations (P < .001) were observed between fR and rating of perceived exertion during both 15:30-second (r = .87) and 30:15-second protocols (r = .85). Conclusions: Our findings suggest that fR is a good marker of physical effort during shuttle-run HIIT in soccer players. These findings have implications for monitoring training in soccer and other team sports.
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Aagaard, P., E. B. Simonsen, J. L. Andersen, S. P. Magnusson, J. Halkjær-Kristensen, and P. Dyhre-Poulsen. "Neural inhibition during maximal eccentric and concentric quadriceps contraction: effects of resistance training." Journal of Applied Physiology 89, no. 6 (December 1, 2000): 2249–57. http://dx.doi.org/10.1152/jappl.2000.89.6.2249.
Full textAbstract:
Despite full voluntary effort, neuromuscular activation of the quadriceps femoris muscle appears inhibited during slow concentric and eccentric contractions. Our aim was to compare neuromuscular activation during maximal voluntary concentric and eccentric quadriceps contractions, hypothesizing that inhibition of neuromuscular activation diminishes with resistance training. In 15 men, pretraining electromyographic activity of the quadriceps muscles [vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF)] was 17–36% lower during slow and fast (30 and 240°/s) eccentric and slow concentric contractions compared with fast concentric contractions. After 14 wk of heavy resistance training, neuromuscular inhibition was reduced for VL and VM and was completely removed for RF. Concurrently, electromyographic activity increased 21–52, 22–29, and 16–32% for VL, VM, and RF, respectively. In addition, median power frequency decreased for VL and RF. Eccentric quadriceps strength increased 15–17%, whereas slow and fast concentric strength increased 15 and 8%, respectively. Pre- and posttraining median power frequency did not differ between eccentric and concentric contractions. In conclusion, quadriceps motoneuron activation was lower during maximal voluntary eccentric and slow concentric contractions compared with during fast concentric contraction in untrained subjects, and, after heavy resistance training, this inhibition in neuromuscular activation was reduced.
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Du, Minghao, Shaolan Bi, Xianfei Zhang, Yaguang Li, Tanda Li, and Ruijie Shi. "Mode angular degree identification in subgiant stars with convolutional neural networks based on power spectrum." Monthly Notices of the Royal Astronomical Society 501, no. 1 (December 22, 2020): 614–22. http://dx.doi.org/10.1093/mnras/staa3642.
Full textAbstract:
ABSTRACT The identification of the angular degrees l of oscillation modes is essential for asteroseismology and it depends on visual tagging before fitting power spectra in a so-called peakbagging analysis. In oscillating subgiants, radial (l = 0) mode frequencies are distributed linearly in frequency, while non-radial (l ≥ 1) modes are p–g mixed modes that have a complex distribution in frequency that increases the difficulty of identifying l. In this study, we trained a one-dimensional convolutional neural network to perform this task using smoothed oscillation spectra. By training simulation data and fine-tuning the pre-trained network, we achieved 95 per cent accuracy for Kepler data.
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Thuany, Mabliny, Thayse Natacha Gomes, and Marcos B. Almeida. "Relationship between Biological, Training, and Physical Fitness Variables in the Expression of Performance in Non-Professional Runners." Sports 9, no. 8 (August 23, 2021): 114. http://dx.doi.org/10.3390/sports9080114.
Full textAbstract:
Sports performance is a multifactorial trait that can be associated with individual and environmental characteristics. In this study, the sample comprised 35 male runners, enrolled in the “InTrack” project. Information regarding variables related to runners’ training was obtained via an online questionnaire, while anthropometric and body composition variables, as well as physical fitness components (muscular power, isometric strength, local muscular endurance, agility, and aerobic capacity) were measured, and a global physical fitness score (based on physical fitness components measured) was computed. The Weltman test (3200 m) was used to estimate runners’ pace and their stride frequency. Linear regression was used, taking the running pace as dependent variable. The final model, comprising biological, physical fitness, spatiotemporal, and training variables, explained 86% of the running performance variance. Muscular power (β = −1.02; 95% CI = (−1.69)–(−0.35)), abdominal muscle endurance (β = −4.81; 95% CI = (−7.52)–(−2.10)), isometric strength (β = −422.95; 95% CI = (−689.65)–(−156.25)), global physical fitness (β = 27.14; 95% CI = 9.52–45.03), and stride frequency (β = −2.99; 95% CI = (−4.29)–(−1.69)) were significantly associated with performance, meaning that better results in tests and increasing the stride frequency leads to better performance. Individual characteristics and physical fitness components were demonstrated to be significant predictors for running performance.