Thermoregulation and marathon performance: relationships of predictability of marathon performance, ambient weather conditions, BSA:MT, BSA:ML, percent body fat, and aerobic fitness

Abstract

The purpose of this study was to observe individual variance in the ability to predict marathon performance from a two-mile time trial performance and determine whether the variance in predictability is influenced by thermoregulatory advantages of body size. Over three distinct marathon conditions, 126 (n =17 in 2010, n =42 in 2011, n =67 in 2012) aerobically-trained college physical activity students participated in pre- and post-anthropometric testing, a two-mile time trial on an indoor track, and concluded with the Eau Claire marathon. Between 72 and 98% of the variance in marathon performance could be explained by two-mile time trial performance. Variation of predicted performance from actual marathon performance was related to body surface area to mass ratio, body surface area to lean mass ratio, and percent body fat but depended on the race temperature, sex, and aerobic fitness. Notably, high body surface area to mass ratio was advantageous for sub-15 minute two-milers racing at an effective temperature of 12 degrees Celcius even though conditions were compensable. (r = 0.399, p< 0.033). The evidence shows that even in cold and mild conditions body surface area to mass ratio can affect marathon performance.