VO2Kinetics and Metabolic Contributions Whilst Swimming at 95, 100, and 105% of the Velocity atVO2 max

A bioenergetical analysis of swimming at intensities near competitive distances is inexistent. It was aimed to compare the transient VO 2 kinetics responses and metabolic contributions whilst swimming at different velocities around VO 2max⁡ . 12 trained male swimmers performed (i) an incremental protocol to determine the velocity at VO 2max⁡ (vVO 2max⁡ ) and (ii) three square wave exercises from rest to 95, 100, and 105% of vVO 2max⁡ . VO 2 was directly measured using a telemetric portable gas analyser and its kinetics analysed through a double-exponential model. Metabolic contributions were assessed through the sum of three energy components. No differences were observed in the fast component response ( τ 1 —15, 18, and 16 s, A 1 —36, 34, and 37 mL · kg −1 · min⁡ −1 , and Gain—32, 29, and 30 mL · min⁡ −1 at 95, 100, and 105% of the vVO 2max⁡ , resp.) but A2 was higher in 95 and 100% compared to 105% intensity (480.76 ± 247.01, 452.18 ± 217.04, and 147.04 ± 60.40 mL · min⁡ −1 , resp.). The aerobic energy contribution increased with the time sustained (83 ± 5, 74 ± 6, and 59 ± 7% for 95, 100, and 105%, resp.). The adjustment of the cardiovascular and/or pulmonary systems that determine O 2 delivery and diffusion to the exercising muscles did not change with changing intensity, with the exception of VO 2 slow component kinetics metabolic profiles.