Neuromuscular performance among power- and endurance-trained athletes

Abstract

The present study was planned to demonstrate possible differences in neuromuscular function and mechanical efficiency (ME) between power- and endurance-trained athletes during natural locomotion. Reflex and voluntary functions were studied in isolated conditions and in the maximal and submaximal stretch-shortening cycle (SSC) exercises (jumping and running). In the reflex conditions, the endurance group was more responsive to mechanical stimuli because of obvious dominance of the slow twitch fibers. In the maximal voluntary conditions for knee extensors and plantarflexors, the power athletes produced higher forces with higher rates of force production. However, the respective EMG-time curve did not differ between the subject groups suggesting that the observed differences are primarily of structural origin. In the maximal jumping exercises, the power athletes were also able to produce high preactivation of leg extensor muscles and successive high and smooth eccentric activity. Additionally in the concentric phase of the take-off, they showed rapid EMG recovery. In the submaximal jumping and running, ME was quite similar in all conditions among both subject groups. This might be due to the endurance athletes having more developed oxidative metabolic functions, whereas the power group demonstrated better neuromuscular function. In other words, higher ME could physiologically be achieved by improved economy of the performance or by the better utilization of elasticity. It is therefore suggested that the training background and/or the inherited structures cause differences between the athletic groups in neuromuscular function and in muscle metabolism. However, in many cases these differences were more individual and, therefore, there appeared no influence on ME in group analysis.