Effect of the rest interval duration between contractions on muscle fatigue

We aimed to investigate the effect of rest interval, between successive contractions, on muscular fatigue.

Eighteen subjects performed elbow flexion and extension (30 repetitions) on an isokinetic dynamometer with 80º of range of motion. The flexion velocity was 120º/s, while for elbow extension we used 5 different velocities (30, 75, 120, 240, 360º/s), producing 5 different rest intervals (2.89, 1.28, 0.85, 0.57 and 0.54 s).

We observed that when the rest interval was 2.89 s there was a reduction in fatigue. On the other hand, when the rest interval was 0.54 s the fatigue was increased.

When the resting time was lower (0.54 s) the decline of work in the flexor muscle group was higher compared with different rest interval duration.