Energetics of competitive swimming. Implications for training programmes.

An analysis of the mechanics and energetics of swimming reveals that different factors play key roles in success in competitive swimming events. Knowledge of these performance factors will help the development of optimal training programmes, especially when their relative importance can be identified. One approach to doing this is to evaluate the energy cost of swimming and the energy generating systems that cover these costs. It appears that the rate of energy expenditure is related to the velocity, the gross efficiency, the propelling efficiency and a drag factor. Energy is generated by aerobic and anaerobic processes. A balance should exist between the energy necessary to swim a distance in a certain time and the total energy available in this time from the energy producing system. This balance was used to predict the performance times over difference distances and to predict the effect of a 10% increase in the aerobic capacity, the anaerobic capacity or the propelling efficiency on the performance times, while keeping all other factors constant. The 10% increase in propelling efficiency resulted in both a reduction in time over the short distance as well as an improvement in performance over the long distance which was superior to the gains found when increasing the maximal aerobic or anaerobic power by 10%. It is concluded that for an optimal use of training time and for an optimal use of the capacities of the swimmer, it seems important to determine both the mechanical parameters (technique, drag) and the parameters describing the energy production. By determining the weak and strong points of competitive swimmers, the optimal training distances and what performance factors are the weakest and most likely to improve with training can be determined.