Projected Sprint Performances are Biologically Unreasonable: 2105 3:45 PM - 4:00 PM

Purpose

According to a recent analysis of Tatem et al. (Nature, 431, September 2004), the trends of men's and women's Olympic 100m times predict that by the middle of the next century women will out sprint men, with a predicted time of 8.08s. In the present study an energy flow model was used to test if it is feasible for humans, male or female, to run 100m in ∼8 seconds.

Methods

A simulation model for running was constructed, including expressions for power production and power losses. The anaerobic and aerobic mechanical power production were described by first-order systems, based on data collected from elite athletes in our laboratory. Power losses were modeled as the mechanical power used to overcome air friction and the mechanical power necessary to accelerate and decelerate body segments, based on data from the literature. Power production was evaluated to obtain the amount of power required to run a given time for the 100m sprint.

Results

To realize the times achieved during the 2004 Olympic 100m sprint finals, an average power output of 16.42 W kg^-1 and 20.82 W kg^-1 is needed for women and men respectively. The relationship between average power output and the resulting 100m times is shown in the figure. To run 100m in 8.08s, as is predicted by Tatem et al., an average power output of 32.75 W kg^-1 is necessary.

Figure. No caption a...

Conclusions

The relation between 100m sprint time and average power output is not linear. Female athletes would need to double their average power output to run 8.08s, males would need >50% increase. This calculation assumes no change in limb mass or frontal area, both of which would have to increase given the anaerobic nature of this event. Because of the relation between anaerobic capacity and muscle volume this would require a doubling of active muscle mass in females. This increase is not feasible within current species body size parameters, thus we question the validity of the fundamental assumptions presented by the recent analysis by Tatem et al.