Validity of Average Power, Total Work, and Exercise Energy Expenditure Quantified by Cycling Mechanics

• Tanja Oosthuyse ^[1] ; Nazeera Bownes ^[1] ; Lauren A. Wiemers ^[1] ; Andrew Bosch ^[1]
  1. [1] University of Cape Town

     University of Cape Town

     City of Cape Town, Sudáfrica

     
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 39, Nº. 11, 2025, págs. 1138-1147
• Idioma: inglés
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• Resumen

  • Average power, work, and exercise energy expenditure (EEE) are useful metrics in cycling for gauging training load and targeting energy intake. These metrics are easily obtained from bicycle-mounted power meters but not all cyclists train with power meters. We used the laws of mechanics to estimate average power, total work, and EEE compared with power-meter measurements during n = 100 training sessions (n = 32 on road bicycles; n = 68 on mountain bikes [MTBs]) in competitive cyclists, with p < 0.05 as significant. Physics-derived average power and power-meter measures had a good agreement (Watts, mean difference +/- SD -1.04 +/- 10.38; SEM 1.038; coefficient of variability 4.2%; intraclass correlation coefficient 0.93), producing estimates of total work (-2 +/- 24 kcal) and EEE (-10 +/- 120 kcal) with negligible mean differences. Although average power was similar (MTB: 2.21 +/- 0.31 W[middle dot]kg-1; road: 2.24 +/- 0.34 W[middle dot]kg-1), total force produced (F Total) was greater in MTB than in road training (25.8 +/- 4.6 N; 20.7 +/- 3.0 N). The components of F Total differed, where forces to overcome gradient (12.9 +/- 5.2 N; 8.5 +/- 3.1 N) and rolling resistance (8.2 +/- 1.6 N; 3.9 +/- 1.1 N) were greater in MTB, and frictional air drag (4.7 +/- 1.9 N; 8.4 +/- 2.3 N) was greater in road training. Using the methodology applied, the laws of cycling mechanics produce fair measures of average power, total work, and EEE for cyclists without bicycle-mounted power meters. In addition, deriving the respective force components could support training prescription and equipment adjustments to optimize performance.