# High-Intensity interval training reduces transcriptomic age: A randomized controlled trial

PMID: 37078430
Journal: Aging Cell
Published: 2023-04-20
Authors: Lohman T, Bains G, Cole S, Gharibvand L, Berk L, Lohman E

## Question

Does 4 weeks of low-dose HIIT reduce transcriptomic age and age acceleration in sedentary middle-aged adults compared with no-exercise control?

## Summary

In sedentary adults aged 40 to 65, 4 weeks of supervised low-dose HIIT reduced an RNA-based transcriptomic age estimate compared with no-exercise control. Body fat, BMI, visceral fat, depression score, and sleep quality improved within the exercise group, but most body-composition differences were not significant between groups and the biological-age marker is a surrogate outcome.

## Population

- Sedentary adults aged 40 to 65 years
- Sample size: 30
- Age: 40 to 65 years
- Sex: 20 women and 10 men
- Fitness level: Low activity/nonexercisers
- Health status: Sedentary adults screened for exercise safety and medication exclusions

## Methodology

- Single-site single-blinded randomized controlled trial
- 4 weeks
- Loma Linda University physical fitness laboratory
- Randomized and controlled study design.

## Protocol

- 10 x 1 HIIT.
- Modality: Rower, cycle ergometer, treadmill.
- Work intervals: 1 min.
- Recovery: 1 min self-selected intensity rest.
- Sets or repetitions: 10 intervals.
- Intensity: 77% to 93% predicted HRmax.
- Session duration: 23 min.
- Frequency: 3 sessions/week.
- Program length: 4 weeks.
- Progression: Effort adjusted to remain in HR target boundaries.
- No-exercise control.
- Modality: Usual activity.
- Program length: 4 weeks.

## Outcomes

### Transcriptomic age
Status: improved
HIIT reduced transcriptomic age while control increased nonsignificantly.

HIIT -3.59 years, p=0.043; control +3.29 years, p=0.078; group x time p=0.026.

### Age acceleration
Status: improved
HIIT reduced transcriptomic age acceleration compared with control.

HIIT -3.84 years, p=0.042; control +3.21 years, p=0.077; group x time p=0.025.

### Body composition
Status: mixed
BMI, body fat mass, and visceral fat area improved within the HIIT group, but between-group differences were not significant.

Between-group p>0.05 for BFM, BMI, and visceral fat area.

## Practical Insights

- A 23-min, 10 x 1-min format is a practical low-dose HIIT template.
- Transcriptomic-age findings are promising but should be framed as surrogate and exploratory.
- HR boundaries can help standardize relative intensity for sedentary adults.

## Limitations

- Small sample
- Short 4-week duration
- No long-term follow-up
- Surrogate biological-age outcome
- TRAP model overestimated age in all samples
- Exploratory pathway analysis used liberal thresholds

## Safety And Adherence

- No adverse-event statement was found in the extracted NXML.
- Participants were screened for exercise safety and monitored with real-time HR during HIIT.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/37078430/) (pubmed)
- [DOI](https://doi.org/10.1111/acel.13841) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10265161/) (full text)

## Agent Guidance

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