The purpose of this study was to investigate how maximal power output (P[subscript max]), as measured via the inertial load technique, changes throughout a collegiate soccer season in relation to training load completed. Furthermore, this study also aimed to describe the time course of recovery of [maximal power output] following two collegiate soccer matches in one weekend. The current investigation involved two experimental periods. The first took place throughout the 2010 Big XII soccer season. Nineteen Division I female collegiate soccer players (19.9 ± 1.2 yrs, 165.1 ± 6.6 cm, 61.0 ± 6.8 kg) from the same collegiate soccer team completed regular inertial load testing and perceptual fatigue questionnaires throughout this study period. These athletes' training was not altered in any way by the investigators throughout the 2010 season. During the second experimental period, two off-season matches were played in one weekend during the 2011 off-season. Training was prescribed by coaches, with the aim of simulating an in-season training week. [Maximal power output] and perceptual fatigue responses were monitored every day throughout the second study period. All training and matches throughout the study were monitored via the session RPE method. The results demonstrated that STARTERS experience much greater load throughout the season than NON-STARTERS (p<0.05, 2247 ± 176 AU and 1585 ± 174 AU), accounted for by increased load experienced during matches. This increased training load throughout the season lead to a decline in [maximal power output] in STARTERS (to 92.3 ± 6%, p<0.05) whilst [maximal power output] was maintained in NON-STARTERS (p>0.05) for the duration of the season. Furthermore, STARTERS experienced greater muscle soreness throughout the in-season period compared to NON-STARTERS. During the second experimental period [maximal power output] declined (p<0.05, 93.3 ± 7%) two days following matches played on the weekend and remained reduced for three days. Notably, two heavy training days in the middle of the training week appeared to have detrimental effects on both [maximal power output] and perceptual fatigue responses. The main finding of this study is that [maximal power output] declined throughout the middle and latter parts of the season in STARTERS, after experiencing significantly greater training loads than NON-STARTERS throughout the season. The current findings, combined with previous investigations, suggest that the inertial load technique may be useful in monitoring fatigue in team sport athletes. / text

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No. of bitstreams: 1 pabloramondomingos.pdf: 1334747 bytes, checksum: 7427028f3e6306db0c724acca7cc7684 (MD5) Previous issue date: 2017-07-28 / O objetivo foi descrever e comparar uma sessão de treinamento de força no Tirante Musculador® (TM) com uma sessão no meio agachamento guiado (MA), e também a recuperação dos participantes após a execução de ambos exercícios. 19 voluntários de ambos os sexos (10 do feminino e 9 do masculino), com média de idade de 17,4 ± 1,5 anos (58,7 ± 9,2 kg de massa corporal; 170,1 ± 9,1 cm de estatura; 35,1 ± 11,5 mm no somatório de dobras cutâneas), atletas de atletismo. Foram realizados dez encontros. No encontro 1 foi randomizada à escolha de qual exercício seria realizado primeiro, e foram realizadas a avaliação antropométrica e o teste de 1RM de um exercício, e após 72h realizaram quatro séries de oito movimentos com 80% do 1RM (encontro 2), e a cada 24h foram realizados testes para a avaliação da recuperação, até 72h (encontros 3, 4 e 5), e para o segundo exercício todo o procedimento foi repetido (encontros de 6 a 10). Durante os encontros 2 e 7 foram realizadas coletas da EMG dos músculos vasto lateral (VL), reto femoral (RF) e vasto medial (VM) e medida a velocidade de execução dos movimentos, já para os encontros de 3 ao 5 e de 8 ao 10, foram realizadas medidas da escala de qualidade total de recuperação (QTR), de dor muscular de início tardio (DMIT), contração voluntária isométrica máxima (CVIM), EMG do VL durante a CVIM e salto com contra movimento (SCM). Não houve diferença na EMG entre os dois exercícios (p>0,05), porém, o RF apresenta um tamanho de efeito grande (1,07), sugerindo maior participação do mesmo na execução do TM do que no MA, não encontrando diferença também entre a potência gerada no TM e no MA (p>0,05). Quando comparada a recuperação do TM com a do MA não encontramos diferença para nenhuma das variáveis medidas (p>0,05). Sendo assim, concluímos que tanto o TM, quanto o MA são bons exercícios para desenvolver a potência, e neste tipo de protocolo se recuperam rapidamente. O TM apresenta certa vantagem em relação ao MA devido às cargas externas absolutas serem menores que no MA e apresentarem respostas internas iguais. Qualitativamente, o efeito da carga aplicada parece durar mais tempo no TM do que no MA, mas, ambos acontecem na mesma magnitude, sendo assim, é necessário que novos estudos sejam realizados de maneira crônica para que se possa compreender de fato os possíveis efeitos. / The aim was to describe and compare a strength training session in the Tirante Musculador® (TM) with a session in the half squat guided (HS), and also the recovery of participants after the execution of both exercises. 19 volunteers of both sexes (10 female and 9 male), with an average age of 17.4 ± 1.5 years (58.7 ± 9.2 kg of body weight; 170.1 ± 9.1 cm stature; 35.1 ± 11.5 mm in the sum of skinfolds), track and field athletes. Ten meetings were held. On the meeting 1 was randomized to the choice of which exercise would be did first, anthropometric evaluation and the test of 1RM of exercise chosen were carried out, and after 72 hours performed four series of eight movements with 80% of 1RM (meeting 2), and every 24 hours did tests for the evaluation of recovery, until to 72 hours (3, 4 and 5 meetings) and for the second exercise the entire procedure was repeated (6 to 10 meetings). During the 2 and 7 meetings were captured electromyographic sings (EMG) of muscle which Vastus lateralis (VL), Rectus Femoris (RF) and Vastus medialis (VM) and measure the execution speed of the movements, to the meetings of 3 to 5 and 8 to 10, were collect total quality recovery scale measures (TRQ), delayed onset muscle soreness (DOMS), maximum isometric voluntary contraction, (MIVC), EMG of the VL during the MIVC and a counter movement jump (CMJ). There was no difference in the EMG between the two exercises (p > 0.05), however, the RF features a large effect size (1.07), suggesting greater participation on implementation of TM than in HS, finding no difference also between the power generated in the TM and HS (p > 0.05). When compared to TM recovery with the HS did not find a difference to any of the variables (p > 0.05). Thus, we conclude that both the TM, as HS are good exercises to develop the power, and in this protocol type recover quickly. The TM presents a certain advantage when compared with the HS due to absolute external loads are smaller than in the HS and submit internal responses alike. Qualitatively, the effect of the applied load seems to last longer in TM than in MA, but both happen on the same magnitude, therefore, it is necessary that new studies be conducted in chronic way in order to understand the possible effects.

Skridskoåkning är en avgörande faktor för prestation i ishockey och styrka (i nedre extremitet) är i sin tur avgörande för hur snabb spelaren är på isen. Syftet med denna studie är att undersöka sambandet mellan power off-ice och skidskosnabbhet på is. Sju män 19.5 ± 0.5 år vid ett gymnasium ställde upp i studien och genomförde ett testbatteri bestående av Ishockeyförbundets styrketester samt Effektmätning vid knäböj. Variabler i dessa styrketester korrelerades sedan mot deltagarnas resultat i skridskotestet Acceleration &amp; Speed för att bestämma vilka styrkevariabler som är relevanta för skridskosnabbhet. Resultaten visade signifikanta samband mellan absolut styrka i frivändning och tid på total skridskosträcka (ρ=0.77, p&lt;0.05) samt hastighetssträckan (ρ=0.77, p=&lt;0.05). Signifikant samband kunde även påvisas mellan relativ styrka i frivändning och hastighetssträckan (ρ=0.71, p&lt;0.05). Slutsatsen av denna studie är att delar av testbatteriet är relevant för att anskaffa information om en spelares maximala åkhastighet. / Skating is a key factor for a successful ice hockey player and strength in the lower extremity is therefore a crucial factor for determination of a players speed on the ice. The purpose of this study was to investigate the correlation between power, tested off-ice, and skating speed on ice. Seven male ice hockey players aged 19.5 ± 0.5 years were recruited from a local highschool. They completed a test battery consisting of the Swedish Ice hockey associations strength tests and power measurements in squat. In order to determine which strength variable is the most relevant to skating speed the strength variables were correlated to the results in a skating test called Acceleration and Speed. The results showed significant correlations between 1RM in clean and time on total distance (ρ=0.77, p&lt;0.05) and velocity (ρ=0.77, p=&lt;0.05) in the skating test. A significant correlation was also found between relative strength in clean and velocity (ρ=0.71, p&lt;0.05). The conclusion of this study was that parts of the testing battery is relevant for use when collecting information on a players maximum skating speed.

L’objectif de ce travail de thèse était d’étudier, selon une approche intégrative, les facteurs intrinsèques et extrinsèques influençant les performances mécaniques et neuromusculaires lors d’exercices de sprint de courte durée sur ergocycle. La première étude a examiné l’effet du genre et le type d’exercice sur la reproductibilité des indices de la relation force-vitesse sur ergocycle. Les résultats ont révélé que la reproductibilité de la relation force-vitesse était plus élevée chez les hommes et au niveau des membres inférieurs comparativement respectivement aux femmes et aux membres supérieurs. La deuxième étude a investigué l’effet de deux charges (8,7 et 11% de la masse corporelle, BM) sur la reproductibilité des indices de puissance mécanique au court d’un test de Wingate. Les résultats ont révélé une reproductibilité comparable entre les deux charges. Cependant, la puissance était plus élevée à 11% BM. La troisième étude a comparé les indices de puissance de la relation force-vitesse et du test de Wingate selon l’aptitude anaérobie des sujets. Les résultats ont montré que la puissance maximale était sous-estimée lors des tests de Wingate réalisés contre des charges non optimales (8,7% BM) notamment chez les sujets sportifs. La quatrième étude a exploré l’effet du contexte émotionnel sur la performance neuromusculaire lors d’exercices de sprints répétés. Les résultats ont révélé un effet positif du contexte plaisant comparativement au contexte déplaisant sur la performance neuromusculaire. Ces résultats suggèrent que la motivation extrinsèque affecte, via la valence émotionnelle (plaisir-déplaisir), la performance lors des exercices maximaux de courte durée. / The aim of the present work was to study, using an integrative approach, the effects of intrinsic and extrinsic factors that influence the mechanical and neuromuscular performances during sprint exercises on a cycle ergometer. The first study examined the effect of exercise and gender on the reliability of the mechanical measurements from the force-velocity tests. The results showed that the reliability of the force-velocity test was higher in men and lower limbs compared to women and upper limbs, respectively. The second study investigated the effect of two loads (8.7 and 11% of body mass, BM) on the reproducibility of mechanical power indices during a Wingate test. The results showed comparable reliability between the two loads. However, power output was significantly higher at 11% BM. The third study compared power indices computed from the force-velocity and Wingate tests among two groups of male subjects with different physical fitness. The results showed that the Wingate tests performed against non-optimal loads (8.7% BM) underestimated maximal power especially in powerful subjects. The fourth study investigated the effect of the emotional context on neuromuscular performance during repeated cycling sprints. The results revealed a positive effect of pleasant context on neuromuscular performance compared to the unpleasant context. These results suggest that extrinsic motivation affects via the emotional valence (pleasant-unpleasant) the performance during all-out exercises.

Deep learning has proven to be a valued contributor to recent technological advancements within energy systems. This thesis project explores methods of photovoltaic (PV) system power output forecasting through the utilization of long short-term memory (LSTM) neural networks. An encoder-decoder architecture (ED-LSTM) and a stacked vector output architecture (SVO-LSTM) were compared in terms of their ability to accurately produce power output forecasts with a 24-hour forecast horizon. The datasets which were used for model training were composed of historical meteorological observations and PV system power output readings. The results indicate that the encoder-decoder model and the stacked vector output model were somewhat equally skilled at producing power output forecasts. Best results were obtained by the encoder-decoder LSTM model which achieved a 26.63% improvement over a persistence model when trained on data sequences which preceded the forecast horizon, and a 44.96% improvement over a persistence model when the model was provided meteorological data from an oracle forecaster.

The main Target of this diploma is to find some reconciliation with cooperation of turbine and ejector. This work is containing informations about this mechanisms and also its historical development. The merits of this diploma thesis is thermodynamics calculation and proposal of main parameters and proportions of the turbine and the ejector. After this it is follow by the calculation of whole system of the turbine and ejector in consequence with calculation of turbine with by-pass regulation and also comparison of power output with ejector and with by-pass technology.

No description available.

In track cycling sprint events, optimal cadence PRopt is a dynamic aspect of fatigue. It is currently unclear what cadence is optimal for an athlete’s performance in sprint races and how it can be calculated. We examined fatigue-induced changes in optimal cadence during a maximal sprint using a mathematical approach. Nine elite track cyclists completed a 6-s high-frequency pedaling test and a 60-s isokinetic all-out sprint on a bicycle ergometer with continuous monitoring of crank force and cadence. Fatigue-free force-velocity (F/v) and power-velocity (P/v) profiles were derived from both tests. The development of fatigue during the 60-s sprint was assessed by fixing the slope of the fatigue-free F/v profile. Fatigue-induced alterations in PRopt were determined by non-linear regression analysis using a mono-exponential equation at constant slope. The study revealed that PRopt at any instant during a 60-s maximal sprint can be estimated accurately using a mono-exponential equation. In an isokinetic mode, a mean PRopt can be identified that enables the athlete to generate the highest mean power output over the course of the effort. Adding the time domain to the fatigue-free F/v and P/v profiles allows time-dependent cycling power to be modelled independent of cadence.

No description available.

Introduction Performance in cross-country skiing is influenced by the skier’s ability to continuously produce propelling forces and force magnitude in relation to the net external forces. A surrogate indicator of the “power supply” in cross-country skiing would be a physiological variable that reflects an important performance-related capability, whereas the body mass itself is an indicator of the “power demand” experienced by the skier. To adequately evaluate an elite skier’s performance capability, it is essential to establish the optimal ratio between the physiological variable and body mass. The overall aim of this doctoral thesis was to investigate the importance of body-mass exponent optimization for the evaluation of performance capability in cross-country skiing. Methods In total, 83 elite cross-country skiers (56 men and 27 women) volunteered to participate in the four studies. The physiological variables of maximal oxygen uptake (V̇O2max) and oxygen uptake corresponding to a blood-lactate concentration of 4 mmol∙l-1 (V̇O2obla) were determined while treadmill roller skiing using the diagonal-stride technique; mean oxygen uptake (V̇O2dp) and upper-body power output (Ẇ) were determined during double-poling tests using a ski-ergometer. Competitive performance data for elite male skiers were collected from two 15-km classical-technique skiing competitions and a 1.25-km sprint prologue; additionally, a 2-km double-poling roller-skiing time trial using the double-poling technique was used as an indicator of upper-body performance capability among elite male and female junior skiers. Power-function modelling was used to explain the race and time-trial speeds based on the physiological variables and body mass. Results The optimal V̇O2max-to-mass ratios to explain 15-km race speed were V̇O2max divided by body mass raised to the 0.48 and 0.53 power, and these models explained 68% and 69% of the variance in mean skiing speed, respectively; moreover, the 95% confidence intervals (CI) for the body-mass exponents did not include either 0 or 1. For the modelling of race speed in the sprint prologue, body mass failed to contribute to the models based on V̇O2max, V̇O2obla, and V̇O2dp. The upper-body power output-to-body mass ratio that optimally explained time-trial speed was Ẇ ∙ m-0.57 and the model explained 63% of the variance in speed. Conclusions The results in this thesis suggest that V̇O2max divided by the square root of body mass should be used as an indicator of performance in 15-km classical-technique races among elite male skiers rather than the absolute or simple ratio-standard scaled expression. To optimally explain an elite male skier’s performance capability in sprint prologues, power-function models based on oxygen-uptake variables expressed absolutely are recommended. Moreover, to evaluate elite junior skiers’ performance capabilities in 2-km double-poling roller-skiing time trials, it is recommended that Ẇ divided by the square root of body mass should be used rather than absolute or simple ratio-standard scaled expression of power output. / <p>Incorrect ISBN in printed thesis: 973-91-7601-270-3</p>