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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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EFFECTS OF BETWEEN-SET INTERVENTIONS ON NEUROMUSCULAR FUNCTION DURING ISOKINETIC MAXIMAL CONCENTRIC CONTRACTIONS OF THE KNEE EXTENSORS |
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Carole Cometti1,2, Gaelle Deley1,2 and Nicolas Babault1,2  |
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1Centre d'expertise de la performance, Faculté des Sciences du Sport, Université de Bourgogne, and 2INSERM/U Motricité et Plasticité, UFR STAPS, Dijon Cedex, Dijon, France |
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© Journal of Sports Science and Medicine (2011) 10, 624 - 629 |
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| ABSTRACT | |||
| The presents study investigated the effects of between-set interventions
on neuromuscular function of the knee extensors during six sets of 10 isokinetic
(120°·s-1) maximal concentric contractions separated by three minutes. Twelve
healthy men (age: 23.9 ± 2.4 yrs) were tested for four different between-set
recovery conditions applied during two minutes: passive recovery, active
recovery (cycling), electromyostimulation and stretching, in a randomized,
crossover design. Before, during and at the end of the isokinetic session,
torque and thigh muscles electromyographic activity were measured during
maximal voluntary contractions and electrically-evoked doublets. Activation
level was calculated using the twitch interpolation technique. While quadriceps
electromyographic activity and activation level were significantly decreased
at the end of the isokinetic session (-5.5 ± 14.2 % and -2.7 ± 4.8 %; p
< 0.05), significant decreases in maximal voluntary contractions and
doublets were observed after the third set (respectively -0.8 ± 12.1% and
-5.9 ± 9.9%; p < 0.05). Whatever the recovery modality applied, torque
was back to initial values after each recovery period. The present results
showed that fatigue appeared progressively during the isokinetic session
with peripheral alterations occurring first followed by central ones. Recovery
interventions between sets did not modify fatigue time course as compared
with passive recovery. It appears that the interval between sets (3 min)
was long enough to provide recovery regardless of the interventions. Key words: Electromyography, electromyostimulation, stretching, recovery, maximal strength. |
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