# Reduced-exertion high-intensity interval training (REHIT) provides limited improvement in post-prandial and 24-hour glycemia in healthy, physically active men

PMID: 41743231
Journal: Journal of exercise science and fitness
Published: 2026 Apr
Authors: Chaudhry BA, Morrell JS, Cook SB, Goodwin NJ, Brian MS

## Question

Does one bout of REHIT performed after a mixed breakfast improve 3-hour post-prandial and 24-hour continuous-glucose-monitor outcomes compared with non-exercise rest in physically active middle-aged men?

## Summary

In healthy physically active middle-aged men, a single 10-minute REHIT cycling bout after breakfast caused a faster drop from post-meal glucose peak to nadir and briefly lower glucose at 65-70 minutes, but did not reduce average 3-hour post-breakfast glucose, 3-hour AUC, 24-hour mean glucose, or 24-hour glucose variability compared with a quiet-rest control day. This is an acute crossover study, not a training study, and its practical glycemic benefit appears limited in this already healthy active group.

## Population

- Healthy physically active middle-aged men.
- Sample size: 20
- Age: 52 +/- 8 years.
- Sex: Male.
- Fitness level: Physically active; mean VO2max 44.5 +/- 6.0 mL/kg/min.
- Health status: Healthy, normal BMI, fasting glucose below diabetes threshold.

## Methodology

- Randomized counterbalanced crossover acute intervention study.
- Single acute REHIT condition and single non-exercise condition, separated by at least 48 hours.
- Laboratory visits with continuous glucose monitor and cycle ergometer.
- Randomized and controlled study design.

## Protocol

- REHIT.
- Modality: Cycling.
- Work intervals: Two 20-s all-out sprints.
- Recovery: Unloaded cycling within a 10-min session.
- Sets or repetitions: 2 sprints.
- Intensity: All-out against 5% body weight; >120% max wattage criterion met.
- Session duration: 10 min.
- Frequency: Single acute bout.
- Program length: Single visit.
- Progression: No progression; one familiarization sprint.
- Non-exercise rest.
- Modality: Seated quiet rest.
- Intensity: Rest.
- Session duration: 10 min plus 30 min post-condition sitting.
- Frequency: Single visit.
- Program length: Single condition.

## Outcomes

### 3-hour mean glucose
Status: no clear change
REHIT did not reduce average 3-hour post-breakfast glucose or AUC compared with non-exercise.

113 +/- 22 vs 114 +/- 19 mg/dL, p=0.809; AUC p=0.856.

### Post-prandial glucose timing
Status: improved
REHIT shortened glucose peak-to-nadir time and briefly lowered glucose at 65 and 70 min.

Peak-to-nadir 41.8 +/- 29.3 vs 67.3 +/- 30.1 min, p=0.014; condition x time p<0.001.

### 24-hour glucose
Status: no clear change
REHIT did not lower 24-hour mean glucose or variability metrics.

24h mean glucose 119 +/- 14 vs 117 +/- 13 mg/dL, p=0.453; SD p=0.173; MAGE p=0.474; CV p=0.746.

### REHIT sprint fidelity
Status: improved
All participants met or exceeded sprint intensity criteria.

Average sprint intensities 155.2 +/- 15.7% and 159.6 +/- 17.7% of peak workload.

## Practical Insights

- A very short REHIT bout should not be sold as meaningfully improving daily glucose in already active healthy men.
- Transient glucose-curve effects may not translate into clinically meaningful glycemic exposure changes.
- REHIT evidence for metabolic benefit is more relevant to repeated training or higher-risk populations than this acute healthy sample.

## Limitations

- Acute single-bout design.
- Men only.
- Healthy physically active sample.
- Physical activity data missing for 7 participants.
- Caffeine intake differed between conditions.

## Safety And Adherence

- Participants obtained physician clearance for maximal exercise.
- No adverse events were described in the reviewed sections.
- All-out sprint protocol may require screening and familiarization.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41743231/) (pubmed)
- [DOI](https://doi.org/10.1016/j.jesf.2026.200452) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12930057/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.