The effects of interval–exercise duration and intensity on oxygen consumption during treadmill running

SummaryThe magnitude of improvement in peak oxygen uptake (V˙O2 peak) and performance to an exercise training regime is related to the V˙O2 of prior accumulated exercise training bouts. However, it is unclear whether constant rate training (CRT) or interval training (INT) preferentially alters the V˙O2 of running exercise. Therefore, the purpose of this study was to compare the acute V˙O2 response to constant, and interval training sessions. Consequently, this study compared the mean average V˙O2 of 17 moderately trained participants to a 20-min CRT and two different 20 min INT treadmill runs. Participants completed three treatments (twice) in random order over 3 weeks. In 1 min INT participants completed 10 × 1 min efforts at the velocity corresponding to V˙O2 peak(Vpeak) interspersed with 10 × 1 min efforts at 0.5Vpeak. In the 2 min INT, participants completed 5 × 2 min efforts at the Vpeak interspersed with 5 × 2 min efforts at 0.5 at Vpeak. In CRT participants ran at a velocity equivalent to the mean velocity of INT (75% Vpeak). Mean average V˙O2 for 2 min INT, 1 min INT and CRT were, respectively, 3200 ± 661; 3076 ± 6041; 2909 ± 584 ml min−1. Both INT sessions resulted in a significantly higher mean average V˙O2 than CRT. Furthermore, 2 min INT resulted in 90% of V˙O2 peak being exceeded more frequently than 1 min INT. We conclude that INT serves as a more potent stimulus for improvement in V˙O2 peak and subsequent endurance performance than CRT.