Different work rate distributions elicit similar time spent near V̇O2max during short-duration interval sessions

Background: Time spent near V̇O2max has been suggested as an optimal stimulus for the promotion of greater V̇O2max improvements. Thus, this study aimed to compare time spent above 90% (t90V̇O2max) and 95% of V̇O2max (t95V̇O2max) during three cycling interval training protocols with decreasing, increasing, or constant work rate distributions within each exercise interval.Methods: After an incremental test to determine V̇O2max and peak power output (Ppeak), ten physically active male individuals (age 28 ± 5 years, V̇O2max 48.4 ± 8.1 mL.kg-1.min-1) performed in a random order three work-matched cycling interval training sessions comprising 8 60 s efforts with 60 s passive recovery. The power output was held constant (100%Ppeak; ITCON), decreasing (from 110 to 90%Ppeak; ITDEC), or increasing (from 90 to 110%Ppeak; ITINC) throughout each work interval. Time sustained above 90% and 95% of V̇O2max, above 90% and 95% of maximal heart rate (t90HRmax; t95HRmax), blood lactate concentrations (BLC), and rating of perceived exertion (RPE) were measured. Results: There was no difference in t90V̇O2max among sessions (ITCON 152 ± 72 s, ITDEC 157 ± 81 s, ITINC 161 ± 81 s, p = .857), t95V̇O2max (ITCON 84 ± 65 s, ITDEC 86 ± 87 s, ITINC 99 ± 73 s, p = .585), t90HRmax (p = .204), t95HRmax (p = .119), BLC (p = .694), or RPE (p = .482). Conclusions: Short-duration cycling interval training around Ppeak induces similar time spent near V̇O2max, regardless of the work rate distribution.