The influence of evaluation protocol on time spent exercising at a high level of oxygen uptake during continuous cycling

AIM: This study evaluated the effects of protocol variation on the time spent exercising at ≥95% .VO2max during cycle ergometer trials performed at the exercise intensity associated with .VO2max (i .VO2max). METHODS: Nine male triathletes (age: 32±10 years; body mass: 73.3±6.1 kg; stature: 1.79±0.07 m; .VO2max: 3.58±0.45 L.min-1) performed four exercise tests. During tests 1 and 2, participants performed a maximal incremental cycle ergometer test using different stage durations (1 min and 3 min) for the determination of i .VO2max (1 min) and i .VO2max (3 min). During tests 3 and 4, participants performed a continuous bout of exhaustive cycling at i .VO2max (1 min) (CONT1) and i .VO2max (3 min) (CONT3). RESULTS: i .VO2max (1 min) was significantly greater (P<0.001) than i .VO2max (3 min) (340±31 W vs. 299±44 W). Time to exhaustion (TTE) measured during CONT3 was significantly longer (P<0.001) than CONT1 (529±140 s vs. 214±65 s). Time spent at .VO2max was significantly longer (P=0.036) during CONT3 than CONT1 (146±158 s vs. 11±20 s), and time spent at ≥95% .VO2max was significantly longer (P=0.005) during CONT3 than CONT1 (326±211 s vs. 57±51 s). CONCLUSION: These results show that when exercising continuously at i .VO2max, time spent at ≥95% .VO2max is influenced by the initial measurement of i .VO2max.