[The effect of body constitution on work capacity evaluated by means of mechanical efficiency]

The utilizable sources of energy of the human organism are relatively restricted where by interindividual differences are not substantial, while differences in physical performance are extreme. The capacity to transform chemical energy into mechanical work, sometimes described also as the work capacity of the organism is evaluated by means of mechanical efficiency--ME. In men with varying amounts of training (incl. untrained ones), differing significantly as to the percentage of body fat (3.8-17.2%), assessed by measurement of ten skinfolds, the authors assessed ME on a treadmill. The highest ME values were recorded in trained sportsmen (endurance runners--32.4%), lowest in untrained middle-aged men (16.9%). The authors found a close negative correlation of ME and maximal oxygen consumption per kg body weight and values of body fat percentage. With the increasing percentage of body fat the values of ME decline, the prerequisites for effective transformation of chemical energy of the organism into mechanical work are reduced and the work capacity of the organism declines.