Alternating high-intensity interval training and continuous training is efficacious in improving cardiometabolic health in obese middle-aged men.

Content Provider	Europe PMC
Author	Poon, Eric Tsz-Chun Siu, Parco Ming-Fai Wongpipit, Waris Gibala, Martin Wong, Stephen Heung-Sang
Copyright Year	2021
Abstract	BackgroundHigh-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) alone has been shown to improve metabolic health, but the effects of alternating the two training approaches as often practiced in real life remained unclear.PurposeTo examine the effects of HIIT or MICT alone or alternating HIIT-MICT on cardiometabolic responses in inactive obese middle-aged men.MethodsForty-two participants (age: 42 ± 5 y; BMI: 26.3 ± 2.1 kg m−2) were randomly assigned to four groups: HIIT (12 x 1-min running bouts at 80–90% HRmax interspersed with 1-min active recovery at 50% HRmax), MICT (40-min brisk walk at 65–70% HRmax), alternating HIIT-MICT or a non-exercise control group (CON). Exercise sessions were conducted three times per week for 16 weeks. Maximal oxygen uptake (VO2max), body composition (by bioelectrical impedance analysis), blood pressure, fasting blood glucose, insulin resistance (HOMA-IR) and lipid profile were assessed at baseline and after the 16-week intervention. Enjoyment and self-efficacy were also assessed at the end of intervention.ResultsAll exercise groups showed a similar VO2max increase of ∼15% (HIIT: 34.3 ± 4.4 vs 39.1 ± 5.4; MICT: 34.9 ± 5.0 vs 39.4 ± 7.2; and alternating HIIT-MICT: 34.4 ± 5.0 vs 40.3 ± 4.6 mL kg−1min−1) compared to baseline and CON (all p < 0.05). Weight, BMI, % fat and waist circumference also showed similar reductions in all exercise groups compared to baseline and CON (all p < 0.05). No significant group difference was observed for all blood markers. Compared to baseline, total cholesterol decreased after HIIT-MICT, while HIIT significantly decreased fasting insulin level and improved insulin resistance (p < 0.05). Enjoyment, self-efficacy and adherence were similar among all exercise groups.ConclusionHIIT or MICT alone or alternating HIIT-MICT similarly improve cardiovascular fitness and body composition in obese middle-aged men despite differences in total training volume and time commitment.
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ISSN	1728869X
Journal	Journal of Exercise Science and Fitness [J Exerc Sci Fit]
Volume Number	20
DOI	10.1016/j.jesf.2021.11.003
PubMed Central reference number	PMC8689221
Issue Number	1
PubMed reference number	34987589
e-ISSN	22265104
Language	English
Publisher	The Society of Chinese Scholars on Exercise Physiology and Fitness
Publisher Date	2021-11-23
Access Restriction	Open
Rights License	This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). © 2021 The Society of Chinese Scholars on Exercise Physiology and Fitness. Published by Elsevier (Singapore) Pte Ltd.
Subject Keyword	HIIT Interval exercise Continuous training Weight management Public health
Content Type	Text
Resource Type	Article
Subject	Pharmacology (nursing) Public Health, Environmental and Occupational Health Physical Therapy, Sports Therapy and Rehabilitation Sports Science Pharmaceutical Science