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Cardio Negatively Impacts Strength Training
An article from Physical Sep 2001 issue cited a study from France that appeared in the International Journal of Sports Medicine.
12 competitive triathletes were tested for peak torque of the knee extensors, electromyographic (EMG) activity of the inner and outer thighs, and the height of a counter-movement jump (starting from a standing position, squatting and then jumping). When quadriceps muscle strength was analyzed after the run, researchers found a significant loss in jumping ability and a loss in the eccentric contraction capabilities of both inner and outer thighs.
The decrease in muscular strength followed prolonged running exercise seems to be dependent upon the type of muscular contraction, with a greater loss occurring in eccentric actions that concentric ones. The larger eccentric strength loss was not due to a reduction in neural input but rather to a failure of the contractile mechanism, particularly in fast-twitch fibers.
RECOMMENDATION: Try varying the days on which you do heavy cardiovascular exercise. Do your serious aerobic work on the days you train your upper body, and lay off the running on your leg days.
An article from Physical Sep 2001 issue cited a study from France that appeared in the International Journal of Sports Medicine.
12 competitive triathletes were tested for peak torque of the knee extensors, electromyographic (EMG) activity of the inner and outer thighs, and the height of a counter-movement jump (starting from a standing position, squatting and then jumping). When quadriceps muscle strength was analyzed after the run, researchers found a significant loss in jumping ability and a loss in the eccentric contraction capabilities of both inner and outer thighs.
The decrease in muscular strength followed prolonged running exercise seems to be dependent upon the type of muscular contraction, with a greater loss occurring in eccentric actions that concentric ones. The larger eccentric strength loss was not due to a reduction in neural input but rather to a failure of the contractile mechanism, particularly in fast-twitch fibers.
RECOMMENDATION: Try varying the days on which you do heavy cardiovascular exercise. Do your serious aerobic work on the days you train your upper body, and lay off the running on your leg days.
