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.