Optimal power-to-mass ratios when predicting flat and hill-climbing time-trial cycling

AM Nevill, SA Jobson, RCR Davison, Asker Jeukendrup

Research output: Contribution to journalArticle

14 Citations (Scopus)


The purpose of this article was to establish whether previously reported oxygen-to-mass ratios, used to predict flat and hill-climbing cycling performance, extend to similar power-to-mass ratios incorporating other, often quick and convenient measures of power output recorded in the laboratory [maximum aerobic power (W (MAP)), power output at ventilatory threshold (W (VT)) and average power output (W (AVG)) maintained during a 1 h performance test]. A proportional allometric model was used to predict the optimal power-to-mass ratios associated with cycling speeds during flat and hill-climbing cycling. The optimal models predicting flat time-trial cycling speeds were found to be (W (MAP) m(-0.48))(0.54), (W (VT) m(-0.48))(0.46) and (W (AVG) m(-0.34))(0.58) that explained 69.3, 59.1 and 96.3% of the variance in cycling speeds, respectively. Cross-validation results suggest that, in conjunction with body mass, W (MAP) can provide an accurate and independent prediction of time-trial cycling, explaining 94.6% of the variance in cycling speeds with the standard deviation about the regression line, s=0.686 km h(-1). Based on these models, there is evidence to support that previously reported VO2-to-mass ratios associated with flat cycling speed extend to other laboratory-recorded measures of power output (i.e. Wm(-0.32)). However, the power-function exponents (0.54, 0.46 and 0.58) would appear to conflict with the assumption that the cyclists' speeds should be proportional to the cube root (0.33) of power demand/expended, a finding that could be explained by other confounding variables such as bicycle geometry, tractional resistance and/or the presence of a tailwind. The models predicting 6 and 12% hill-climbing cycling speeds were found to be proportional to (W (MAP) m(-0.91))(0.66) revealing a mass exponent, 0.91, that also supports previous research.
Original languageEnglish
Pages (from-to)424-431
Number of pages8
JournalEuropean Journal of Applied Physiology
Issue number4
Publication statusPublished - 1 Jul 2006


  • power at ventilatory threshold (W-VT)
  • average power output (W-AVG)
  • cycling speed
  • maximal aerobic power (W-MAP)
  • power supply and demand


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