The effect of low-volume high-intensity interval training on cardiometabolic health and psychological responses in overweight/obese middle-aged men

ABSTRACT

High-intensity interval training (HIIT) has been proposed as a time-efficient exercise protocol to improve metabolic health, but direct comparisons with higher-volume moderate-intensity continuous training (MICT) under unsupervised settings are limited. This study compared low-volume HIIT and higher-volume MICT interventions on cardiometabolic and psychological responses in overweight/obese middle-aged men. Twenty-four participants (age: 48.1±5.2yr; BMI: 25.8±2.3kg·m⁻²) were randomly assigned to undertake either HIIT (10 X 1-min bouts of running at 80–90% HR_max separated by 1-min active recovery) or MICT (50-min continuous jogging/brisk walking at 65–70% HR_max) for 3 sessions/week for 8 weeks (2-week supervised + 6-week unsupervised training). Both groups showed similar cardiovascular fitness (VO_2max) improvement (HIIT: 32.5±5.6 to 36.0±6.2; MICT: 34.3±6.0 to 38.2±5.1mL kg⁻¹ min⁻¹, p < 0.05) and %fat loss (HIIT: 24.5±3.4 to 23.2±3.5%; MICT: 23.0±4.3 to 21.5±4.1%, p< 0.05) over the 8-week intervention. Compared to baseline, MICT significantly decreased weight and waist circumference. No significant group differences were observed for blood pressure and cardiometabolic blood markers such as lipid profiles, fasting glucose and glycated haemoglobin. Both groups showed similar enjoyment levels and high unsupervised adherence rates (>90%). Our findings suggest that low-volume HIIT can elicit a similar improvement of cardiovascular fitness as traditional higher-volume MICT in overweight/obese middle-aged men.

KEYWORDS:

• High-intensity interval training
• interval exercise
• cardiometabolic health
• psychological responses
• weight management
• public health

Highlights

• Low-volume HIIT offers cardiometabolic health benefits, especially for cardiovascular fitness, comparable to traditional higher-volume MICT in overweight/obese middle-aged men.

• Low-volume HIIT also shows a similar enjoyment level to MICT and has high adherence in an unsupervised free-living environment.

Acknowledgments

The authors would like to thank Mr. Anthony Chung for his valuable assistance in the collection and analysis of data.

Disclosure statement

No potential conflict of interest was reported by the authors.