Allometric scaling of peak power output accurately predicts time trial performance and maximal oxygen consumption in trained cyclists

Br J Sports Med. 2012 Jan;46(1):36-41. doi: 10.1136/bjsm.2010.083071. Epub 2011 Aug 4.


Objective: The purpose of this study was to determine if peak power output (PPO) adjusted for body mass(0.32) is able to accurately predict 40-km time trial (40-km TT) performance.

Methods: 45 trained male cyclists completed after familiarisation, a PPO test including respiratory gas analysis, and a 40-km TT. PPO, maximal oxygen consumption (VO(2max)) and 40-km TT time were measured. Relationships between 40-km TT performance and (I) absolute PPO (W) and VO(2max) (l/min), (II) relative PPO (W/kg) and VO(2max) (ml/min/kg) and (III) PPO and VO(2max) adjusted for body mass (W/kg(0.32) and ml/min/kg(0.32), respectively) were studied.

Results: The continuous ramp protocol resulted in a similar relationship between PPO and VO(2max) (r=0.96, p<0.0001) compared with a stepwise testing protocol but was associated with a lower standard error of the estimated when predicting VO(2max). PPO adjusted for body mass (W/kg(0.32)) had the strongest relationship with 40-km TT performance (s) (r=-0.96, p<0.0001). Although significant relationships were also found between absolute (W) and/or relative PPO (W/kg) and 40-km TT performance (s), these relationships were significantly weaker than the relationship between 40-km TT performance and PPO adjusted for body mass (W/kg(0.32)) (p<0.0001).

Conclusions: VO(2max) can be accurately predicted from PPO when using a continuous ramp protocol, possibly even more accurately than when using a stepwise testing protocol. 40-km TT performance (s) in trained cyclists can be predicted most accurately by PPO adjusted for body mass (W/kg(0.32)). As both VO(2max) and 40-km TT performance can be accurately predicted from a PPO test, this suggests that (well)-trained cyclists can possibly be monitored more frequently and with fewer tests.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Athletic Performance / physiology*
  • Bicycling / physiology*
  • Body Constitution / physiology
  • Energy Metabolism / physiology
  • Humans
  • Male
  • Middle Aged
  • Oxygen Consumption / physiology*
  • Predictive Value of Tests
  • Time Factors
  • Young Adult