Intensity-dependence of exercise and active recovery in high-intensity interval training

Kemi, O. J. , Fowler, E., Mcglynn, K., Primrose, D., Smirthwaite, R. and Wilson, J. (2019) Intensity-dependence of exercise and active recovery in high-intensity interval training. Journal of Sports Medicine and Physical Fitness, 59(1), pp. 1937-1943. (doi: 10.23736/S0022-4707.19.09521-5)

Abstract

Background: High-intensity interval training (HIIT) with interspersing active recovery is an effective mode of exercise training in cohorts ranging from athletes to patients. Here, we assessed the intensity-dependence of the intervals and active recovery bouts for permitting a sustainable HIIT protocol. Methods: 14 males completed 4x4-minute HIIT protocols where intensities of intervals ranged 80-100% of maximal oxygen uptake (VO2max) and active recovery ranged 60-100% of lactate (La-) threshold (LT). Blood La- measurements indicated fatigue, while tolerable duration of intervals indicated sustainability. Results: HIIT at 100% of VO2max allowed 44±10% [30-70%] completion, i.e. fatigue occurred after 7minutes:6seconds of the intended 16 minutes of high intensity, whereas HIIT at 95-80% of VO2max was 100% sustainable (p<0.01). Measured intensity did not differ from intended intensity across the protocols (p>0.05). Blood La- concentration [La-] increased to 9.3±1.4mM during HIIT at 100% of VO2max, whereas at 80-95% of VO2max stabilised at 2-6mM in an intensity-dependent manner (p<0.01 vs 100% of VO2max and p<0.05 vs baseline). Active recovery at 60-70% of LT during HIIT associated with steady-state blood [La-] peaking at 6-7mM, whereas at 80-100% of LT, blood [La-] accumulated to 10-13mM (p<0.05). After HIIT, active recovery at 80-90% of LT cleared blood [La-] 90% faster than at 60-70% of LT (p<0.05). Conclusions: To permit highest exercise stress during 4x4-minute HIIT, exercise intensity should be set to 95% of VO2max, whereas active recovery should be set to 60-70% of LT during HIIT and 80-90% of LT after HIIT to most efficiently prevent excess La- and aid recovery.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kemi, Dr Ole and Mcglynn, Miss Karen and Wilson, Mr John
• Authors: Kemi, O. J., Fowler, E., Mcglynn, K., Primrose, D., Smirthwaite, R., and Wilson, J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Medical Veterinary and Life Sciences > School of Life Sciences
• Journal Name: Journal of Sports Medicine and Physical Fitness
• Publisher: Edizioni Minerva Medica
• ISSN: 0022-4707
• ISSN (Online): 1827-1928
• Published Online: 30 April 2019
• Copyright Holders: Copyright © 2019 Edizioni Minerva Medica
• First Published: First published in Journal of Sports Medicine and Physical Fitness 59(12):1937-43
• Publisher Policy: Reproduced in accordance with the publisher copyright policy