Defining the number of bouts and oxygen uptake during the "Tabata protocol" performed at different intensities.

It is usually reported that the Tabata protocol (TP) is performed with eight bouts of 20:10 intervals at a load equivalent to 170% of i V̇ Omax. However, the feasibility of accumulating 160 s of work at 170% i V̇ Omax has been questioned. This article tested the intensity that would allow the performance of the original TP on a cycle ergometer, and measured the highest value of oxygen consumption (V̇ O) obtained during the TP and the time spent above 90% of the maximal oxygen uptake (V̇ Omax) during the TP performed at different intensities. Thirteen young active males (25.9 ± 5.5 years, 67.9 ± 9.2 kg, 1.70 ± 0.06 m, 23.6 ± 3.1 kg·m) participated in the study. Participants performed a graded exertion test (GXT) on a cycle ergometer to obtain maximum oxygen consumption (V̇ Omax) and the intensity associated with V̇ Omax (i V̇ Omax). V̇ O, maximal heart rate (HRmax), and number of bouts performed were evaluated during the TP performed at 115%, 130%, and 170% of i V̇ Omax. V̇ Omax, HRmax, and iV̇ Omax were 51.8 ± 8.0 mL.kg·min, 186 ± 10 bpm, and 204 ± 26 W, respectively. The number of bouts performed at 115% (7 ± 1 bouts) was higher than at 130% (5 ± 1 bouts) and 170% (4 ± 1 bouts) (p < .0001). The highest V̇ O achieved at 115%, 130%, and 170% of iV̇ Omax was 54.2 ± 7.9 mL·kg·min, 52.5 ± 8.1 mL·kg·min, and 49.6 ± 7.5 mL·kg·min, respectively. Non significant difference was found between the highest V̇ O achieved at different intensities, however qualitative magnitude-inference indicate a likely small effect between 115% and 170% of iV̇ Omax. Time spent above 90% of the V̇ Omax during the TP at 115% (50 ± 48 s) was higher than 170% (23 ± 21 s; p < 0.044) with a probably small effect. In conclusion, our data suggest that the adequate intensity to perform a similar number of bouts in the original TP is lower than previously proposed, and equivalent to 115% of the iV̇ Omax. In addition, intensities between 115 and 130% of the iV̇ Omax should be used to raise the time spent above 90% V̇Omax.