The aim of this study was to compare the physiological responses during 15 min of intermittent running consisting of 30 s of high-intensity running exercise at maximal aerobic velocity (MAV) interspersed with 30 s of passive recovery (30-30) performed outdoor versus on a motorized treadmill. Fifteen collegiate physically active males (age, 22 ± 1 years old; body mass, 66 ± 7 kg; stature, 176 ± 06 cm; weekly training volume, 5 ± 2 h·week-1), performed the Fitness Intermittent Test 45-15 to determine maximal oxygen uptake (V̇O2max) and MAV and then completed in random order 3 different training sessions consisting of a 30-s run/30-s rest on an outdoor athletic track (30-30 Track) at MAV; a 30-s run/30-s rest on a treadmill (30-30 Treadmill) at MAV; a 30-s run/30-s rest at MAV+15% (30-30 + 15% MAV Treadmill). Oxygen uptake (V̇O2), time above 90%V̇O2max (t90%V̇O2max), and rating of perceived exertion (RPE) were measured during each training session. We observed a statistical significant underestimation of V̇O2 (53.1 ± 5.4 mL·kg-1·min-1 vs 49.8 ± 6.7 mL·kg-1·min-1, -6.3%, P = 0.012), t90%V̇O2max (8.6% ± 11.5% vs 38.7% ± 32.5%, -77.8%, P = 0.008), RPE (11.4 ± 1.4 vs 16.5 ± 1.7, -31%, P < 0.0001) during the 30-30 Treadmill compared with the same training session performed on track. No statistical differences between 30-30 +15 % MAV Treadmill and 30-30 Track were observed. The present study demonstrates that a 15% increase in running velocity during a high-intensity intermittent treadmill training session is the optimal solution to reach the same physiological responses than an outdoor training session.
Keywords: athletic track; consommation maximale d’oxygène; entraînement par intervalles; interval training; motorized treadmill; oxygen uptake; piste d’athlétisme; tapis roulant.