Exercise modality effect on oxygen uptake off‐transient kinetics at maximal oxygen uptake intensity

New FindingsWhat is the central question of this study? Do the mechanical differences between swimming, rowing, running and cycling have a potential effect on the oxygen uptake ( V ̇ O 2 ) off‐kinetics after an exercise sustained until exhaustion at 100% of maximal oxygen uptake ( V ̇O 2 max ) intensity?What is the main finding and its importance? The mechanical differences between exercise modes had a potential effect and contributed to distinct amplitude of the fast component (higher in running compared with cycling) and time constant (higher in swimming compared with rowing and cycling) in theV ̇ O 2off‐kinetic patterns at 100% ofV ̇O 2 maxintensity. This suggests that swimmers, unlike rowers and cyclists, would benefit more from a longer duration of training intervals after each set of exercise performed atV ̇O 2 maxintensity.The kinetics of oxygen uptake ( V ̇ O 2 ) during recovery (off‐transient kinetics) for different exercise modes is largely unexplored, hampering the prescription of training and recovery to enhance performance. The purpose of this study was to compare theV ̇ O 2off‐transient kinetics response between swimmers, rowers, runners and cyclists during their specific mode of exercise at 100% of maximal oxygen uptake ( V ̇O 2 max ) intensity and to examine the on–off symmetry. Groups of swimmers, rowers, runners and cyclists ( n  = 8 per group) performed (i) an incremental exercise protocol to assess the velocity or power associated withV ̇O 2 max( v V ̇O 2 maxor w V ̇O 2 max, respectively) and (ii) a square‐wave exercise transition from rest tov V ̇O 2 max/v V ̇O 2 maxw V ̇O 2 maxw V ̇O 2 maxuntil volitional exhaustion. Pulmonary exchange parameters were measured using a telemetric portable gas analyser (K4b 2 ; Cosmed, Rome, Italy), and the on‐ and off‐transient kinetics were analysed through a double‐exponential approach. For all exercise modes, both transient periods were symmetrical in shape once they had both been adequately fitted by a double‐exponential model. However, differences were found in the off‐kinetic parameters between exercise modes; the amplitude of the fast component of theV ̇ O 2off‐response was higher in running compared with cycling (48 ± 5 and 36 ± 7 ml kg −1  min −1 , respectively; P  < 0.001), and the time constant of the same phase was higher in swimming compared with rowing and cycling (63 ± 5, 56 ± 5 and 55 ± 3 s, respectively; P  < 0.001). Although both phases were well described by a double‐exponential model, the differences between exercise modes had a potential effect and contributed to distinctV ̇ O 2off‐transient kinetic patterns at 100% ofV ̇O 2 maxintensity.