Evening high-intensity interval training (HIIT) and moderate-intensity interval training (MIIT) produce similar acute changes in circadian core body temperature mesor and phase in adults with obesity, with a borderline non-significant difference in amplitude change.
In a randomized crossover trial of 9 adult males with obesity, evening HIIT (~30 min at 90% HRR) and MIIT (~50 min at 60% HRR) both produced approximately one-hour phase advances in circadian core body temperature rhythm. The change in circadian temperature amplitude differed in direction between conditions (MIIT -0.01 ± 0.19 °C; HIIT +0.12 ± 0.24 °C) but did not reach statistical significance (p = 0.060, d_z = 0.73).
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
Evening high-intensity interval training (HIIT) and moderate-intensity interval training (MIIT) produce similar acute changes in circadian core body temperature mesor and phase in adults with obesity, with a borderline non-significant difference in amplitude change. The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).
The Claim
Evening high-intensity interval training (HIIT) and moderate-intensity interval training (MIIT) produce similar acute changes in circadian core body temperature mesor and phase in adults with obesity, with a borderline non-significant difference in amplitude change.
This conclusion is most relevant to: Nine adult males with obesity (BMI ≥ 25 kg/m², Asia-Pacific criterion).
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Effects of exercise intensity on circadian rhythm and glucose regulation in adults with obesity: a randomized crossover trial. (Physical activity and nutrition, 2026) —
How It Works
The proposed biological pathway:
- ▸Evening exercise acts as a non-photic zeitgeber
- ▸Exercise intensity may differentially affect core body temperature regulation
- ▸Temperature amplitude changes reflect circadian rhythm adjustment
- ▸Result: HIIT and MIIT produce similar phase advances but potentially different amplitude changes
Who Might Benefit
Evidence fit by population:
- ▸Nine adult males with obesity (BMI ≥ 25 kg/m², Asia-Pacific criterion)
Recommended Dose
N/A
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Small sample size (n=9) limits statistical power and generalizability
- ▸Single-session acute design does not assess chronic effects of repeated exercise
- ▸Only males were studied, limiting applicability to females with obesity
Frequently Asked Questions
Does evening exercise disrupt sleep in people with obesity?▼
In this study, neither HIIT nor MIIT significantly affected sleep efficiency, total sleep time, or wake after sleep onset compared to baseline, suggesting evening exercise at these intensities does not impair sleep.
Which exercise intensity is better for glucose regulation in obesity?▼
Twenty-four-hour mean glucose trended lower after MIIT (95.9 mg/dL) than HIIT (98.7 mg/dL), but the difference was not statistically significant (p = 0.081). Glucose variability did not differ between conditions.
Can evening exercise shift circadian rhythms in people with obesity?▼
Yes, both HIIT and MIIT produced approximately one-hour phase advances in core body temperature rhythm, indicating that evening exercise can act as a zeitgeber in adults with obesity.
What was the main finding of this study?▼
The study found that evening HIIT and MIIT produced similar acute changes in circadian mesor and phase, with a borderline non-significant difference in amplitude change favoring HIIT. No significant differences were observed in glucose regulation or sleep quality.
References
- 1.Kim YI, Lee J, Cho S, In J, Seo M, Lee J, Choi Y, Park J. “Effects of exercise intensity on circadian rhythm and glucose regulation in adults with obesity: a randomized crossover trial..” Physical activity and nutrition, 2026. PMID: 42438852 DOI: 10.20463/pan.2026.0029