6533b871fe1ef96bd12d0f26

RESEARCH PRODUCT

Muscle cross-sectional area and voluntary force production characteristics in elite strength- and endurance-trained athletes and sprinters

subject

description

Seven male elite strength-trained athletes (SA) from different weight categories, six elite sprinters (SPA) and seven elite endurance-trained athletes (EA) volunteered as subjects for examination of their muscle cross-sectional area (CSA), maximal voluntary isometric force, force-time and relaxation-time characteristics of the leg extensor muscles. The SA group demonstrated slightly greater CSA and maximal absolute strength than the SPA group, while the EA group demonstrated the smallest values both in CSA and especially in maximal strength (p<0.05). When the maximal forces were related to CSA of the muscles, the mean value for the SA group of 60.8±10.0 N·cm−2 remained slightly greater than that recorded in the SPA group 55.0±3.1 N·cm−2 and significantly greater (p<0.05) than that recorded in the EA group 49.3±4.0 N·cm−2. The mean value in the SPA was also significantly greater (p<0.05) than that of the EA group. The isometric force-time curves differed between the groups (p<0.05−0.01) so that the times taken to produce the same absolute force were the shortest in the SPA group and the longest in the EA group. With force expressed as a percentage of the maximum, the force-time curves showed that the SPA group demonstrated still shorter times to a given value (p<0.05), especially at the lower force levels, than the other two groups. With regard to the differences in force production per CSA and in the shape of the force-time curves, the present findings may be explained by possible differences both in the rate and the amount of neural activation of the muscles and/or in the qualitative characteristics of the muscle tissue itself. The present findings characterize the very specific nature of high resistance strength-, sprint- and endurance-training stimuli over a very prolonged period of time.