Exercise modality effect on bioenergetical performance at VO2max intensity

Abstract

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 subgroups 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 analyzer (K4b2, Cosmed, Rome, Italy) and VO2 kinetics analyzed 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 (mean ± SD: swimming, 187 ± 25; rowing, 199 ± 52; running, 245 ± 46; and cycling, 227 ± 48 s). 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 < 0.001). Conclusion: Although there were different VO2 kinetics and ventilatory patterns, the Tlim-100%VO2max was similar between exercise modes most likely related to the common central and peripheral level of fitness in our athletes.