VO_2max prediction based on submaximal cardiorespiratory relationships and body composition in male runners and cyclists: a population study

Objectives Oxygen uptake (VO₂) is one of the most important measures of fitness and critical vital sign. CPET is a valuable method of assessing fitness in sport and clinical settings. This study aimed to: (1) derive prediction models for maximal VO₂ (VO_2max) based on exercise variables at anaerobic threshold (AT) or respiratory compensation point (RCP) or only somatic and (2) internally validate provided equations.

Methods 4424 male endurance athletes (EA) underwent maximal symptom-limited CPET on a treadmill (n=3330) or cycle ergometer (n=1094). The cohort was randomly divided between: variables selection (n_runners=1998; n_cyclist=656), model building (n_runners=666; n_cyclist=219) and validation (n_runners=666; n_cyclist=219). Random Forest was used to select the most significant variables. Models were derived and internally validated with Multiple Linear Regression.

Results Runners were 36.24±8.45 yrs.; BMI=23.94±2.43 kg·m⁻²; VO_2max=53.81±6.67 mL·min⁻¹·kg⁻¹. Cyclists were 37.33±9.13 yr.; BMI=24.34±2.63 kg·m⁻²; VO_2max=51.74±7.99 mL·min⁻¹·kg⁻¹. VO₂ at AT and RCP were the most contributing variables to exercise equations. Body mass and body fat had the highest impact on the somatic equation. Model performance for VO_2max based on variables at AT was R²=0.81, at RCP was R²=0.91, at AT&RCP was R²=0.91 and for somatic-only was R²=0.43.

Conclusions Derived prediction models were highly accurate and fairly replicable. Formulae allow for precise estimation of VO_2max based on submaximal exercise performance or somatic variables. Presented models are applicable for sport and clinical settling. They are a valuable supplementary method for fitness practitioners to adjust individualised training recommendations.

Funding The author(s) received no specific funding for this work.