Exercise Modality Effect on Bioenergetical Performance at V˙O2max Intensity.

Abstract

A bioenergetical analysis of different exercise modes near maximal oxygen consumption (V˙O2max) 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 V˙O2max and determined the specific oxygen uptake (V˙O2) kinetics and total energy expenditure (Etot-tlim). Four subgroups of 10 swimmers, 10 rowers, 10 runners, and 10 cyclists performed (i) an incremental protocol to assess the velocity (vV˙O2max) or power (wV˙O2max) associated with V˙O2max and (ii) a square wave transition exercise from rest to vV˙O2max/wV˙O2max to assess the time to voluntary exhaustion (Tlim-100%V˙O2max). The V˙O2 was measured using a telemetric portable gas analyzer (K4b, Cosmed, Rome, Italy) and V˙O2 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. No differences were evident in Tlim-100% V˙O2max between exercise modes (mean ± SD: swimming, 187 ± 25; rowing, 199 ± 52; running, 245 ± 46; and cycling, 227 ± 48 s). In contrast, the V˙O2 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). Although there were different V˙O2 kinetics and ventilatory patterns, the Tlim-100%V˙O2max was similar between exercise modes most likely related to the common central and peripheral level of fitness in our athletes.