Fractional Utilization of $\dot{V}$O$_2$max : A Key Performance Determinant in Endurance Sports?

$\textbf{Purpose:}$ Identifying physiological factors that underly elite performance in endurance sports drives the work of many practitioners and researchers. Current models outline the maximal oxygen uptake ($\dot{V}$O$_2$max), fractional utilization of ̇$\dot{V}$O$_2$max (%$\dot{V}$O$_2$max) at lactate threshold (LT) or competition intensity, and gross mechanical efficiency or economy as key determinants of endurance performance. While the importance of $\dot{V}$O$_2$max and efficiency/economy has been confirmed repeatedly, less conclusive evidence has been presented on %$\dot{V}$O$_2$max. In this review, we provide a narrative overview of the current literature on %$\dot{V}$O$_2$max as one of the performance-determining variables in endurance sports, and whether it can be improved through training.

$\textbf{Results:}$ Out of the 35 studies assessing the relationship between %$\dot{V}$O$_2$max and performance, only a few studies confirm a substantial relationship between %$\dot{V}$O$_2$max and performance. This holds for %$\dot{V}$O$_2$max at a specific physiological “landmark,” such as LT and %$\dot{V}$O$_2$max at a competition-specific intensity. ... mehrAdditionally, there is limited evidence suggesting that %$\dot{V}$O$_2$max can be systematically altered through training in trained athletes. Methodological differences in the assessment of $\dot{V}$O$_2$max, LT, and endurance performance across the included studies, as well as variation in the training interventions, confound the interpretation of the findings.

$\textbf{Conclusion:}$ According to the current literature, %$\dot{V}$O$_2$max at LT or competition intensity does not seem to be a strong predictor of endurance performance. Practical recommendations on how to improve %$\dot{V}$O$_2$max via training can currently not be given. We encourage researchers to collect and publish data on %$\dot{V}$O$_2$max for a more comprehensive conclusion about its role for endurance performance.