Highest oxygen consumption prediction: introducing variable theoretical proportional factors for different sports

The use of a fixed theoretical-proportional-factor (TPF₁₅) is one of the indirect highest-oxygen-consumptions (HOC) assessment methods, but it may not accurately reflect the physiological differences across various sports (cycling-triathlon-running-football-multisport). The aim of this study is to evaluate the variability of TPF across different sports, proposing a series of sport-specific new TPF values for more accurate HOC estimation.

A sample of 340 adults (26.01 ± 7.18 years) performed a maximal-incremental-test using sport-specific-ergometers. HOC was considered for cycling  $$ , whereas for the other investigated sports it was considered $$ . HOC was directly measured using a gas-analyzer, and TPF values were calculated using heart rate (HR): the ratio of HR_max/HR_rest multiplied for the measured values of HOC. A one-way ANOVA was used to measure differences and Bland-Altman plots were constructed to compare predicted and actual  $$ / $$ .

Actual HOC was significantly greater than those predicted by the fixed TPF₁₅ (P < 0.001). Sport-specific new TPF values ranged from 16.55 in multisport to 20.15 in cycling, consistently exceeding the old fixed TPF₁₅, and predicting therefore better HOC. The new TPF exhibited a closer agreement with the directly measured $$ / $$  compared to the TPF₁₅. Furthermore, the new TPF reduced the typical-measurement-error (14.94-17.78%) compared to TPF₁₅ (15.63-24.13%).

This study suggests that new TPF values predict $$ / $$  with higher accuracy compared to the traditional method. The use of HR_max and HR_rest values allows to customize training programs for different athletes. Future research should focus on validating these findings across larger populations of athletes.