Abstract

To examine neuromuscular fatigue and recovery 10 male and 9 female athletes performed strenuous heavy resistance exercise. Subjects strained their leg extensor muscles with the same maximal relative intensity by performing 1 maximal squat-lift with a load of 100 of 1 RM 20 times (20x1x100). The session resulted in considerable gradual decreases in maximal force in males by 24.1+-14.4 and in females by 20.5+-11.8 as recorded immediately after the session. Significant decreases also took place in the males in the maximal IEMGs of the exercised muscles, while the corresponding decreases in the females were minor. The force-time curve shifted greatly to the right both in the males and in the females but the average change of 27.8+-13.8 in the males was greater than that of 18.7+-8.3 recorded for the females. The time of force relaxation lengthened in both groups. Maximal force recovered during the first hour of rest was more in the females than in the males but thereafter the recovery took place gradually in both groups to the same degree. The present findings suggest that strenuous heavy resistance loading may result in considerable acute fatigue in the neuromuscular system leading not only to the decreased force production capacity of the muscles but also to a decrease in the voluntary neural activation of the exercised muscles. In males neuromuscular fatigue during strenuous loading may be greater and acute recovery from fatigue slower than in females. Verf.-Referat (gkuerzt)