Energetics of high-speed running: integrating classical theory and contemporary observations

Abstract

We hypothesized that the anaerobic power and aerobic power outputs during all-out runs of any common duration between 10 and 150 s would be proportional to the maximum anaerobic (Ė_an-max) and aerobic powers (Ė_aer-max) available to the individual runner. Seventeen runners who differed in Ė_an-max and Ė_aer-max (5 sprinters, 5 middle-distance runners, and 7 long distance runners) were tested during treadmill running on a 4.6° incline. Ė_an-max was estimated from the fastest treadmill speed subjects could attain for eight steps. Ė_aer-max was determined from a progressive, discontinuous, treadmill test to failure. Oxygen deficits and rates of uptake were measured to assess the respective anaerobic and aerobic power outputs during 11–16 all-out treadmill runs that elicited failure between 10 and 220 s. We found that, during all-out runs of any common duration, the relative anaerobic and aerobic powers utilized were largely the same for sprint, middle-distance, and long-distance subjects. The similar fractional utilization of the Ė_an-max and Ė_aer-max available during high-speed running 1) provides empirical values that modify and advance classic theory, 2) allows rates of anaerobic and aerobic energy release to be quantified from individual maxima and run durations, and 3) explains why the high-speed running performances of different event specialists can be accurately predicted ( R² = 0.97; n = 254) from two direct measurements and the same exponential time constant.