Abstract - Fatigue behavior in strain cycling in the low and intermediate cycle range
Joint-specific power production and fatigue during maximal cycling
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Abstracts / Journal of Science and Medicine in Sport 12 (2010) e1–e232 e53 prognostic categories. It appears to separate the groups ear- lier than the response of serum cortisol to the same bout of heavy-intensity exercise. The area under the curve (AUC) of a Receiver Operating Characteristic is 0.85 indicating this is adequate simple clinical test but further work is required. Combining presenting symptom duration, and the combined responses of serum cortisol and serum ACTH to a bout exer- cise, provides information regarding duration of recovery for the fatigued athlete. doi:10.1016/j.jsams.2009.10.109 109 Joint-specific power production and fatigue during max- imal cycling N. Brown 1,∗ , J. Martin 2 1 Australian Institute Of Sport 2 University of Utah Cycling power decreases substantially during a maximal cycling trial of just 30 s. It is not known whether powers produced at each joint decrease to a similar extent or if each joint exhibits an individual fatigue profile. A finding of joint-specific fatigue during maximal cycling would provide insight into several aspects of fatigue. The purpose of this investigation was to determine the changes in power at each joint during a fatiguing cycling trial. Thirteen trained cyclist performed a 30-s maximal cycling trial on an isokinetic cycle ergometer. Pedal forces and limb kinematics were recorded. Joint powers were calculated for the initial, middle, and final three second intervals of the trial and normalized to initial values. Relative ankle extension power was significantly less than all other joint actions at the middle interval (51 ± 5% of initial power; p = 0.013). Relative ankle extension power for the final interval (37 ± 3%) was significantly less than the relative knee flexion and hip extension power (p = 0.010). Relative knee extension power (41 ± 5%) was significantly less than relative hip extension power (55 ± 4%) during the final three second interval (p = 0.045). Knee flexion power (47 ± 5%) did not differ from relative hip extension power (p = 0.06). These changes in power were accompanied by a decrease in time spent extending by each joint with fatigued (i.e., decreased duty cycle). Because the ankle fatigued more then the hip and knee joints, either peripheral muscle fatigue or changes in motor control strategies were identified as potential fatigue mechanisms during a maximal 30-s cycling trial. Further, because joint powers are dependent on joint angular velocities, riding position and the arrangement of the pedal-shoe interface will likely influences a cyclist’s resis- tance to fatigue under maximal conditions. doi:10.1016/j.jsams.2009.10.110 110 The effect of hydrotherapy recovery on central fatigue: A preliminary examination using transcranial magnetic stimulation S. Cassar 1,∗ , D. Kidgell 2 , A. Pearce 1 1 School of Sport and Exercise Science, Victoria University, Australia 2 Deakin University Insufficient recovery between successive bouts of exercise may lead to subsequent fatigue and consequently a reduction in athletic performance. Several post exercise recovery strate- gies, including various forms of hydrotherapy, have been implemented in an attempt to minimise the effects of fatigue. A limited but growing body of evidence supports the bene- fits of hydrotherapy, however, central nervous system (CNS) fatigue and hydrotherapy recovery has yet to be fully exam- ined. The aim of this study was to investigate the effectiveness of hydrotherapy recovery interventions on central fatigue following repeated cycling performance. Trained male recre- ational cyclists (8 m; 22–35 years of age) participated in a randomised cross-over design of three recovery interventions (cold water immersion (CWI), contrast water therapy (CWT), and passive rest) following exhaustive 30min cycling exer- cise conducted over five days. CNS excitability was assessed using transcranial magnetic stimulation, cycling performance through a time to fatigue (TTF) test, blood markers for mus- cle inflammation and damage, and visual analogue scale for perception of fatigue. All conditions showed a progressive decline in TTF performance (from day 1 to day 5) with CWI and CWT showing significant decreases (p = 0.04) on days three (9.7 and 8.1% respectively), four (14.9 and 12.9% respectively), and five (17.7 and 13.5% respectively). How- ever, for the passive recovery condition, a significant mean decrease (p = 0.04) in performance was observed from days 2 (13.2%) to 5 (30.8%). Similarly CNS excitability showed a progressive decline with CWI and CWT with an initial sig- nificant decrease of 10.2% and 11.8% respectively (p = 0.04). However, CNS excitability did not significantly change for either condition from days three to five (p = 0.14). CNS excitability for the passive recovery condition showed a sig- nificant decline ranging from 25.1% on day two to 30.5% on day five, when compared to day one (p = 0.04). Further, CNS excitability was associated with performance (r = 0.83) and perceptions of fatigue (r = 0.75).The results demonstrate that the hydrotherapies used in this study attenuated the decre- ment in cycling performance and CNS excitability and aided to minimise central fatigue, compared to the passive condi- tion. doi:10.1016/j.jsams.2009.10.111
Transcript of Joint-specific power production and fatigue during maximal cycling
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Abstracts / Journal of Science an
rognostic categories. It appears to separate the groups ear-ier than the response of serum cortisol to the same bout ofeavy-intensity exercise. The area under the curve (AUC) ofReceiver Operating Characteristic is 0.85 indicating this
s adequate simple clinical test but further work is required.ombining presenting symptom duration, and the combined
esponses of serum cortisol and serum ACTH to a bout exer-ise, provides information regarding duration of recovery forhe fatigued athlete.
oi:10.1016/j.jsams.2009.10.109
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oint-specific power production and fatigue during max-mal cycling
. Brown 1,∗, J. Martin 2
Australian Institute Of SportUniversity of Utah
Cycling power decreases substantially during a maximalycling trial of just 30 s. It is not known whether powersroduced at each joint decrease to a similar extent or ifach joint exhibits an individual fatigue profile. A finding ofoint-specific fatigue during maximal cycling would providensight into several aspects of fatigue. The purpose of thisnvestigation was to determine the changes in power at eachoint during a fatiguing cycling trial. Thirteen trained cyclisterformed a 30-s maximal cycling trial on an isokinetic cyclergometer. Pedal forces and limb kinematics were recorded.oint powers were calculated for the initial, middle, and finalhree second intervals of the trial and normalized to initialalues. Relative ankle extension power was significantly lesshan all other joint actions at the middle interval (51 ± 5%f initial power; p = 0.013). Relative ankle extension poweror the final interval (37 ± 3%) was significantly less thanhe relative knee flexion and hip extension power (p = 0.010).elative knee extension power (41 ± 5%) was significantly
ess than relative hip extension power (55 ± 4%) during thenal three second interval (p = 0.045). Knee flexion power47 ± 5%) did not differ from relative hip extension powerp = 0.06). These changes in power were accompanied by aecrease in time spent extending by each joint with fatiguedi.e., decreased duty cycle). Because the ankle fatigued morehen the hip and knee joints, either peripheral muscle fatiguer changes in motor control strategies were identified asotential fatigue mechanisms during a maximal 30-s cyclingrial. Further, because joint powers are dependent on jointngular velocities, riding position and the arrangement of the
edal-shoe interface will likely influences a cyclist’s resis-ance to fatigue under maximal conditions.oi:10.1016/j.jsams.2009.10.110
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cine in Sport 12 (2010) e1–e232 e53
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he effect of hydrotherapy recovery on central fatigue:preliminary examination using transcranial magnetic
timulation
. Cassar 1,∗, D. Kidgell 2, A. Pearce 1
School of Sport and Exercise Science, Victoria University,ustraliaDeakin University
Insufficient recovery between successive bouts of exerciseay lead to subsequent fatigue and consequently a reduction
n athletic performance. Several post exercise recovery strate-ies, including various forms of hydrotherapy, have beenmplemented in an attempt to minimise the effects of fatigue.
limited but growing body of evidence supports the bene-ts of hydrotherapy, however, central nervous system (CNS)atigue and hydrotherapy recovery has yet to be fully exam-ned. The aim of this study was to investigate the effectivenessf hydrotherapy recovery interventions on central fatigueollowing repeated cycling performance. Trained male recre-tional cyclists (8 m; 22–35 years of age) participated in aandomised cross-over design of three recovery interventionscold water immersion (CWI), contrast water therapy (CWT),nd passive rest) following exhaustive 30 min cycling exer-ise conducted over five days. CNS excitability was assessedsing transcranial magnetic stimulation, cycling performancehrough a time to fatigue (TTF) test, blood markers for mus-le inflammation and damage, and visual analogue scale forerception of fatigue. All conditions showed a progressiveecline in TTF performance (from day 1 to day 5) withWI and CWT showing significant decreases (p = 0.04) onays three (9.7 and 8.1% respectively), four (14.9 and 12.9%espectively), and five (17.7 and 13.5% respectively). How-ver, for the passive recovery condition, a significant meanecrease (p = 0.04) in performance was observed from days(13.2%) to 5 (30.8%). Similarly CNS excitability showedprogressive decline with CWI and CWT with an initial sig-ificant decrease of 10.2% and 11.8% respectively (p = 0.04).owever, CNS excitability did not significantly change for
ither condition from days three to five (p = 0.14). CNSxcitability for the passive recovery condition showed a sig-ificant decline ranging from 25.1% on day two to 30.5% onay five, when compared to day one (p = 0.04). Further, CNSxcitability was associated with performance (r = 0.83) anderceptions of fatigue (r = 0.75).The results demonstrate thathe hydrotherapies used in this study attenuated the decre-
ent in cycling performance and CNS excitability and aided
ion.
oi:10.1016/j.jsams.2009.10.111
