PROLONGED EXERCISE FATIGUE IS ASSOCIATED WITH REDUCED MUSCULAR FUNCTIONING
Lepers, R., Hausswirth, C., Maffiuletti, N., Brisswalter, J., & Van Hoecke, J. (2000). Evidence of neuromuscular fatigue after prolonged cycling exercise. Medicine and Science in Sports and Exercise, 32, 1880-1886.
The effects of prolonged cycling exercise on metabolic, neuromuscular, and biomechanical parameters were analyzed. Trained male cyclists (N = 8) performed for two-hours at 65% VO2max. Activity in the vastus lateralis and vastus medialis muscles was recorded.
It was found that oxygen uptake (9.6%), minute ventilation (17.7%), and heart rate (12.7%) increased significantly, whereas pedaling rate (-21%) decreased significantly. Muscular peak torque was reduced (-11 to -15%) in concentric, isotonic, and isometric contractions of the two muscles. Significant decreases in maximal twitch tension, total area of mechanical response, and maximal rate of twitch tension development, were recorded postexercise.
Implication. A reduction in muscular capacity after prolonged cycling was associated with reduced neural input to the muscles and a failure of peripheral contractile mechanisms.
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