Neuromuscular fatigue following high versus low-intensity eccentric exercise of biceps brachii muscle.
OBJECTIVE
This study investigated neuromuscular fatigue following high versus low-intensity eccentric exercise corresponding to the same amount of work.


METHODS
Ten volunteers performed two eccentric exercises of the elbow flexors: a high-intensity versus a low-intensity exercise. Maximal voluntary contraction torque and surface electromyography of the biceps brachii muscle were recorded before, immediately and 48 h after exercises. Maximal voluntary activation level, neural (M-wave) and contractile (muscular twitch) properties of the biceps brachii muscle were analysed using electrical stimulation techniques.


RESULTS
Maximal voluntary contraction torque was significantly (P<0.01) reduced immediately and 48 h after exercise but the reduction was not different between the two conditions. Electromyography associated with maximal voluntary contraction significantly decreased (P<0.05) immediately and 48 h after exercise for both conditions while maximal voluntary activation level was only significantly reduced immediately after the high-intensity exercise. Peak twitch alterations were observed immediately and 48 h after exercise for both conditions while M-wave did not change.


CONCLUSIONS
High and low-intensity eccentric exercises with the same amount of work induced the same reduction in maximal strength capacities of the biceps brachii muscles. The magnitude of peripheral and central fatigue was very similar in both conditions.
Gauche
Elodie
E
Laboratory of Biomechanics and Physiology, Research Department, National Institute of Sport and Physical Education, INSEP, 11 Avenue du Tremblay, 75012 Paris, France.
Couturier
Antoine
A
Lepers
Romuald
R
Michaut
Anne
A
Rabita
Giuseppe
G
Hausswirth
Christophe
C
D000328:Adult; D004551:Elbow Joint / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*