Exercise modality effect on bioenergetical performance at VO2max intensity.

PURPOSE: A bioenergetical analysis of different exercise modes near maximal oxygen consumption (VO2max) intensity is scarce, hampering the prescription of training to enhance performance. We assessed the time sustained in swimming, rowing, running and cycling at an intensity eliciting VO2max and determined the specific oxygen uptake (VO2) kinetics and total energy expenditure (Etot-tlim). METHODS: Four sub-groups of 10 swimmers, 10 rowers, 10 runners and 10 cyclists performed: (i) an incremental protocol to assess the velocity (vVO2max) or power (wVO2max) associated with VO2max and (ii) a square wave transition exercise from rest to vVO2max/wVO2max to assess the time to voluntary exhaustion (Tlim-100%VO2max). The VO2 was measured using a telemetric portable gas analyser (K4b, Cosmed, Rome, Italy) and VO2 kinetics analysed using a double exponential curve fit. Etot-tlim was computed as the sum of its three components: aerobic (Aer), anaerobic lactic (Analac) and anaerobic alactic (Anaalac) contributions. RESULTS: No differences were evident in Tlim-100%VO2max between exercise modes (swimming 187 ± 25, rowing 199 ± 52, running 245 ± 46 and cycling 227 ± 48 s; mean ± SD). In contrast, the VO2 kinetics profile exhibited a slower response in swimming (21 ± 3 s) compared with the other three modes of exercise (rowing 12 ± 3, running 10 ± 3 and cycling 16 ± 4 s) (P<0.001). Etot-tlim was similar between exercise modes even if the Analac contribution was smaller in swimming compared with the other sports (P