Exercise ventilatory efficiency in elite athletes assessed for the Paris 2024 Olympic Games: The effect of sex and sport categories

Ventilatory efficiency during cardiopulmonary exercise testing (CPET) is obtained by relating minute ventilation (V'_E) to CO₂ output (V'CO₂). Limited information is available regarding exercise ventilatory efficiency in young elite athletes. We assessed ventilatory efficiency in elite athletes; evaluating the influence of sex and/or ESC sport categories; evaluating the agreement between the V'_E/V'CO₂ slope and nadir in measuring ventilatory efficiency; evaluating differences between subgroups of athletes stratified by ventilatory efficiency. A cohort of 443 elite athletes prospectively underwent CPET. The slope (s₁) and the intercept of the linear region of the V'_E/V'CO₂ relationship, the V'_E/V'CO₂ value at the lactate threshold and the V'_E/V'CO₂ nadir were used to assess ventilatory efficiency. Male athletes and endurance athletes, both males and females, had higher exercise ventilatory efficiency (p < 0.001). A strong positive correlation was observed between V'_E/V'CO₂ s₁ and nadir (p < 0.001). Of note, both high (V'_E/V'CO₂ s₁ < 24) and very high (V'_E/V'CO₂ s₁ < 22) levels of ventilatory efficiency were associated with greater exercise tolerance (i.e., peak oxygen uptake, maximal power; p < 0.001). The results of our study emphasize the need to include the measurement of ventilatory efficiency in the evaluation of elite athletes, potentially refining their training strategies.