Metabolic And Hemodynamic Responses To High Intensity Interval Training With Various Recovery Intervals

Abstract

For more than twenty years, the Tabata protocol has provided the basis for high intensity interval training (HIIT). Although the improvements associated with the protocol are laudable, an intensity of 170% of max VO2, is difficult for even highly motivated athletes to achieve. A repeated bout HIIT protocol at 100% of Max VO2 may be a more tolerable option, if it achieves a similar metabolic stress. PURPOSE: The purpose was to determine the metabolic cost of 8 repetitions of HIIT at a workload equivalent to 100% Max VO2 (HIIT) for 20 sec with recovery intervals of 10, 20, 30 and 40 sec at 20% of Max VO2. METHODS: 14 recreationally active college-age students (age: 21.6±1.1 yrs., height: 171.410.5 cm, body mass: 75.0±10.6 kg, max VO2 2.89±.67, 8 ♂) volunteered to participate in a randomized, single-blind crossover design study with a minimum of 4 days between trials. A max VO2 ramp protocol on a Lode Cycle ergometer preceded the HIIT trials and established the max workload. VO2 was obtained by continuous open circuit spirometry and blood lactate by finger puncture. Excess Post Exercise O2 Consumption (EPOC) was obtained for 20 min. RESULTS: Statistical analysis by ANOVA with repeated measures (P<.05) was applied to the following data.CONCLUSION: The prescribed HIIT work intervals provide ample metabolic stimulus, however recovery intervals in excess of 30 seconds substantially attenuate the oxygen uptake, while still requiring a strong anaerobic contribution. The use of eight repeat bouts of HIIT at a workload equivalent to 100% of max VO2 may be a viable alternative to the traditional Tabata protocol.