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Updated: May 9, 2026
A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass
Tomoaki Matsuo1, Kousaku Saotome, Satoshi Seino
11Space Biomedical Research Office, Japan Aerospace Exploration Agency, Tokyo, JAPAN; 2Hazard Evaluation and Epidemiology Research Group, National Institute of Occupational Safety and Health, Kawasaki, JAPAN; 3Center for Cybernics Research, University of Tsukuba, Tsukuba, JAPAN; 4Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, JAPAN; and 5Faculty of Sport and Health Science, Ritsumeikan University, Kyoto, JAPAN.
Purpose:
The aim of this study was to compare the effects of time-efficient, low-volume interval exercises on cardiorespiratory capacity and left ventricular (LV) mass with traditional continuous exercise in sedentary adults.
Methods:
Forty-two healthy but sedentary male subjects (age 26.5 ± 6.2 yr) participated in an 8-wk, five times per week, supervised exercise intervention. They were randomly assigned to one of three exercise protocols: sprint interval training (SIT, 5 min, 100 kcal), high-intensity interval aerobic training (HIAT, 13 min, 180 kcal), and continuous aerobic training (CAT, 40 min, 360 kcal). Cardiorespiratory capacity (V˙O2max) and LV mass (3T-MRI) were measured preintervention and postintervention.
Results:
We observed significant (P < 0.01) increases in V˙O2max in all three groups, and the effect of the HIAT was the greatest of the three (SIT, 16.7% ± 11.6%; HIAT, 22.5% ± 12.2%; CAT, 10.0% ± 8.9%; P = 0.01). There were significant changes in LV mass, stroke volume (SV), and resting HR in both the SIT (LV mass, 6.5% ± 8.3%; SV, 5.3% ± 8.3%; HR, -7.3% ± 11.1%; all P < 0.05) and HIAT (LV mass, 8.0% ± 8.3%; SV, 12.1% ± 9.8%; HR, -12.7% ± 12.2%; all P < 0.01) but not in the CAT (LV mass, 2.5% ± 10.1%; SV, 3.6% ± 6.6%; HR, -2.2% ± 13.3%; all P > 0.05).
Conclusions:
Our study revealed that V˙O2max improvement with the HIAT was greater than with the CAT despite the HIAT being performed with a far lower volume and in far less time than the CAT. This suggests that the HIAT has potential as a time-efficient training mode to improve V˙O2max in sedentary adults.
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