The Effects of Different Training Backgrounds on VO2 Responses to All-Out and Supramaximal Constant-Velocity Running Bouts

To investigate the impact of different training backgrounds on pulmonary oxygen uptake (V̇O₂) responses during all-out and supramaximal constant-velocity running exercises, nine sprinters (SPRs) and eight endurance runners (ENDs) performed an incremental test for maximal aerobic velocity (MAV) assessment and two supramaximal running exercises (1-min all-out test and constant-velocity exercise). The V̇O₂ responses were continuously determined during the tests (K4^b2, Cosmed, Italy). A mono-exponential function was used to describe the V̇O₂ onset kinetics during constant-velocity test at 110%MAV, while during 1-min all-out test the peak of V̇O₂ (V̇O₂peak), the time to achieve the V̇O₂peak (tV̇O₂peak) and the V̇O₂ decrease at last of the test was determined to characterize the V̇O₂ response. During constant-velocity exercise, ENDs had a faster V̇O₂ kinetics than SPRs (12.7 ± 3.0 vs. 19.3 ± 5.6 s; p < 0.001). During the 1-min all-out test, ENDs presented slower tV̇O₂peak than SPRs (40.6 ± 6.8 and 28.8 ± 6.4 s, respectively; p = 0.002) and had a similar V̇O₂peak relative to the V̇O₂max (88 ± 8 and 83 ± 6%, respectively; p = 0.157). Finally, SPRs was the only group that presented a V̇O₂ decrease in the last half of the test (-1.8 ± 2.3 and 3.5 ± 2.3 ml.kg^-1.min^-1, respectively; p < 0.001). In summary, SPRs have a faster V̇O₂ response when maximum intensity is required and a high maximum intensity during all-out running exercise seems to lead to a higher decrease in V̇O₂ in the last part of the exercise.