Repeated anaerobic tests predict performance among a group of advanced CrossFit-trained athletes

High-intensity functional training (HIFT) (i.e., CrossFit (CF) training) uses a combination of movements and self-selected time periods of work and rest. However, little is known about the physiological responses to an acute bout of HIFT exercise or about the physical parameters that distinguish performance. The purpose of this study was to examine the physiological responses in advanced CF athletes to consecutive Wingate trials with short, active recovery periods. Twenty-nine advanced-level CF-trained athletes volunteered for this study. The participants were required to complete 4 consecutive Wingate anaerobic tests (WAnTs) and a 15-min CF-style workout. Across the 4 WAnT trials, significant (p < 0.001) changes were observed in oxygen consumption, respiratory exchange ratio, and heart rate. Significant (p ≤ 0.001) differences among WAnT trials were observed in all anaerobic performance measures. Compared with all other trials, greater peak power (p < 0.04), relative peak power (p < 0.02), average power (p < 0.001), relative average power (p < 0.001), and total work (p < 0.001), together with a lower fatigue index (p < 0.01), were observed during WAnT 1. Overall, the 4 consecutive WAnT trials resulted in a significant (F = 177.0, p < 0.001) increase in blood lactate response. Stepwise regression revealed that the ability to predict total repetitions completed during the 15-min trial to complete as many repetitions as possible improved as the participants progressed from the first to the third WAnT trial. Our data suggest that, combined with the ability to better maintain performance across high-intensity exercise bouts, the ability to quickly recover between bouts is the most important factor in CF performance.