Intermittent vs Continuous Graded Exercise Test for VO2max in College Soccer Athletes

Abstract

The purpose of this study was to determine if a 1-min active recovery between stages during a graded exercise test (GXT) would result in a higher stage intensity and maximum oxygen uptake in college soccer athletes. Eleven athletes completed two GXT protocols on separate days. Each GXT consisted of 2-min stages performed at a constant running speed and incremental increases of 2.5% grade. One GXT was performed continuously and the other was intermittent with 1-min active recovery between each stage. Tests were performed to volitional fatigue. Following the each GXT and a 10-min active recovery period, participants performed a verification stage at an intensity greater than the final stage of the GXT. All participants completed a higher intensity stage during the intermittent vs continuous GXT. As a result, VO2max and maximum heart rate (HR) were significantly higher (VO2: 57.7 ± 5.8 vs. 55.5 ± 5.7 ml•kg-1•min-1, HR: 190 ± 6 vs. 187 ± 6 bpm, p < 0.02) during the intermittent GXT. Maximum ventilation and respiratory exchange ratio did not differ between intermittent and continuous protocols. Following the intermittent GXT, nine participants completed the verification stage and obtained VO2 values within the plateau criterion. We conclude that a continuous GXT underestimates VO2max in some athletes and that the intermittent protocol may provide a more accurate measure of VO2max.