# High-Intensity Interval Training Is Feasible in Women at High Risk for Breast Cancer

PMID: 31269007
Journal: Medicine and Science in Sports and Exercise
Published: 2019-06-20
Authors: Coletta AM, Brewster AM, Chen M, Li Y, Bevers TB, Basen-Engquist K, Gilchrist SC

## Question

Is supervised treadmill HIIT feasible and safe for overweight or obese postmenopausal women at high risk for breast cancer, and how do preliminary fitness effects compare with MICT and usual care?

## Summary

In overweight or obese postmenopausal women at high risk for breast cancer, a supervised 12-week treadmill HIIT program was feasible, with retention and adherence similar to moderate continuous training. HIIT improved cardiorespiratory fitness more clearly than usual care, but the small trial was not powered to determine cancer prevention or broad body-composition effects.

## Population

- Postmenopausal overweight/obese women at high risk for breast cancer.
- Sample size: 44
- Age: Mean 63.9 +/- 8.8 years.
- Sex: Female.
- Fitness level: Not athlete sample; medically screened prevention population.
- Health status: High breast cancer risk; overweight/obese.

## Methodology

- Three-arm randomized feasibility trial.
- 12 weeks.
- Supervised clinical exercise setting at MD Anderson Cancer Prevention Center.
- Randomized and controlled study design.

## Protocol

- HIIT.
- Modality: Treadmill.
- Work intervals: 4 min at 90-100% HRpeak.
- Recovery: 3 min active recovery at 50-70% HRpeak.
- Sets or repetitions: 4 intervals.
- Intensity: HRpeak-based; recalibrated after 6-week CPET.
- Session duration: 33 min.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: Intensity zones recalibrated at week 6; energy expenditure matched to MICT.
- MICT and usual care.
- Modality: Treadmill continuous exercise for MICT; education/phone support for usual care.
- Work intervals: Continuous 41-min exercise for MICT.
- Intensity: MICT at 60-70% HRpeak.
- Session duration: 41 min for MICT.
- Frequency: 3 sessions/week for MICT; monthly calls for usual care.
- Program length: 12 weeks.
- Progression: HRpeak zones recalibrated after 6-week CPET for exercise groups.

## Outcomes

### Feasibility
Status: improved
HIIT had high adherence among completers and similar adverse event counts to MICT.

Retention 33/42 among baseline-intending participants; adherence 90% HIIT and 89% MICT.

### Cardiorespiratory fitness
Status: improved
HIIT improved VO2peak, peak METs, and treadmill exercise time; usual care improved less than HIIT.

VO2peak versus usual care +0.15 L/min, p = .005; relative +2.3 mL/kg/min, p = .004.

### Exercise time
Status: improved
HIIT improved treadmill time more than both comparators.

+101 s versus MICT and +125 s versus usual care, p < .001.

### Body weight and BMI
Status: no clear change
No significant group effect for weight or BMI.

p > .05.

## Practical Insights

- 4 x 4 min treadmill HIIT can be feasible in a screened clinical prevention population when supervised.
- Safety screening matters; symptoms occurred even in a supervised trial.
- Fitness outcomes are stronger than weight outcomes.

## Limitations

- Small feasibility trial.
- Underpowered for secondary outcomes.
- Supervised clinic setting limits scalability.
- Special high-risk postmenopausal population.
- No cancer incidence endpoint.

## Safety And Adherence

- No serious adverse events were reported.
- Six HIIT adverse events and four MICT adverse events were reported.
- Two exercise sessions were discontinued because of shortness of breath or dizziness.
- Muscle soreness and joint pain were listed as possibly related.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/31269007/) (pubmed)
- [DOI](https://doi.org/10.1249/MSS.0000000000002048) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7028472/) (full text)

## Agent Guidance

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