Contrast of methods for calculating internal work of running for trained and untrained runners.

Abstract

This research contrasted two methods for calculating the internal work of running. The methods are known as absolute work (also known as Winter's (1979) W$\sb{\rm wb}$ calculation) and absolute power. The study also examined whether or not there were differences in the amounts of internal work done by trained and untrained runners. The absolute work approach was believed to calculate internal work incorrectly. The absolute power approach, on the other hand, correctly computes internal work by taking the absolute power generated or absorbed at each joint and summing them across a movement cycle. Five trained and five untrained female runners were filmed, while running across a laboratory runway, by a cinecamera at 100 fps. Simultaneously, force plate data, for one step, were collected. The results showed absolute work values were three times the absolute power values. Furthermore, the results of the absolute work method were too large compared to the estimated physiological cost of running. Conversely, the absolute power method produced amounts of internal work that were too high but were much closer to the estimated physiological cost. There was no significant difference between work values of the two groups of runners, for the absolute power method. The correlations for the absolute power method were higher than those of the absolute work method. Based on the results, the absolute power method provided a more accurate estimate of locomotor cost of running.