Relationship in Peak Power That May Exist Between Maximal Isokinetic Cycle Sprints and Maximal Isokinetic Leg Extensions

5.0 Discussion

The present study was carried out to investigate any relationship in peak power that may exist between maximal isokinetic cycle sprints and maximal isokinetic leg extensions, on the premise that the same major muscle groups are employed during both activities.

The Maximal isokinetic 8 second sprints elected a mean (( SD) peak power output of   834.16 W (( 75.70, n = 8) which was achieved at a mean (( SD) angle of 136º (( 35.62).   The mean (( SD) peak power obtained during maximal dynamic isokinetic leg extensions equalled 347.46 W (( 76.45), with the mean (( SD) angle at which peak power was elicited being 136º (( 35.62).   Hence the peak power output of maximal constant velocity leg extensions equates to 41.65% of that achieved within the maximal isokinetic dynamic cycle sprints.

No significant relationship (P>0.05. n = 8) between peak power achieved during maximal dynamic isokinetic leg extensions and maximal dynamic isokinetic leg extensions was reported.   Therefore the first experimental hypothesis can be rejected and the second hypothesis accepted.   A possible explanation for this may be that subjects did not perform maximally over the isokinetic leg extension repetitions (due to lack of familiarisation), with the activity only being performed over one angular velocity (270º / s-1, 4.725 radians / s-1).

As the motion of leg extension is that over a horizontal plane and not that of a vertical plane the gravitational effect of the isokinetic movement should in theory have no influential effect on the results obtained (Herzog, 1988).   However when performing multiple repetitions at or near to maximal power output velocities, most subjects take three contractions to reach their peak.   This peak can not be reproduced for more than a single contraction before a progressive decline in performance is recorded (Perrine, 1986).   As suggested by Perrine the energy requirements associated with...