# Cardiovascular Health Does Not Change Following High-Intensity Interval Training in Women with Polycystic Ovary Syndrome

PMID: 35329952
Journal: Journal of clinical medicine
Published: 2022 Mar 15
Authors: Kiel IA, Jones H, Lionett S, Røsbjørgen R, Lydersen S, Vanky E, Moholdt T

## Question

Do women with PCOS differ from BMI- and age-matched women without PCOS in cardiovascular risk markers, and does 16 weeks of HIIT change those markers?

## Summary

This secondary analysis of PCOS exercise trials found that 16 weeks of semi-supervised HIIT had little effect on selected cardiovascular risk markers in women with PCOS. Resting heart rate decreased within the PCOS HIIT group, but FMD, IMT, MMP-9, and most blood pressure/metabolic markers did not improve. Low adherence and lifestyle changes in the control group make the cardiovascular findings hard to interpret.

## Population

- Women aged 18-45 with PCOS by Rotterdam criteria plus age- and BMI-matched women without PCOS.
- Sample size: 79
- Age: 18-45 years; most participants 18-39
- Sex: Women only
- Fitness level: Excluded regular endurance training >=2 times/week
- Health status: PCOS or non-PCOS controls; excluded cardiovascular disease, other endocrine disorders, pregnancy/breastfeeding, and relevant hormone/metabolic medications

## Methodology

- Secondary analysis of a two-center RCT in women with PCOS plus case-control HIIT trial in women without PCOS
- 16 weeks
- Semi-supervised treadmill/outdoor walking or running in Norway and Australia
- Randomized and controlled study design.

## Protocol

- Pooled PCOS HIIT.
- Modality: Treadmill walking/running supervised; outdoor walking/running allowed unsupervised.
- Work intervals: Either 4 minutes or 1 minute depending on assigned HIIT protocol.
- Recovery: HV-HIIT: 3 minutes active recovery at about 70% HRmax; LV-HIIT: 1 minute low-intensity walking or passive recovery.
- Sets or repetitions: HV-HIIT: 4 x 4 minutes; LV-HIIT: 10 x 1 minute.
- Intensity: HV-HIIT 90-95% HRmax; LV-HIIT maximal intensity participants could sustain.
- Session duration: HV-HIIT about 38 minutes including 10 minute warm-up and 3 minute cool-down; LV-HIIT about 33 minutes including warm-up/cool-down.
- Frequency: Offered 3 sessions/week; up to 2 could be unsupervised.
- Program length: 16 weeks.
- Progression: Not described in this paper.
- PCOS non-exercise control.
- Modality: Habitual activity and diet.
- Intensity: Advised about general recommendation of at least 150 min/week moderate activity.
- Program length: 16 weeks.

## Outcomes

### Resting heart rate
Status: improved
Resting heart rate declined within the PCOS HIIT group.

PCOS HIIT p=0.037; abstract reports -2.8 beats/min, 95% CI -5.4 to -0.2.

### Vascular function
Status: mixed
Women without PCOS increased resting brachial artery diameter after HIIT, while PCOS HIIT showed a different time-to-peak dilation response versus non-PCOS HIIT; FMD did not clearly improve.

Non-PCOS resting diameter +0.12 mm, 95% CI 0.01 to 0.24, p=0.038; time-to-peak difference PCOS HIIT vs Non-PCOS HIIT 55 s, 95% CI 13 to 96, p=0.012.

### MMP-9
Status: no clear change
MMP-9 did not differ by PCOS status and did not change within or between groups after 16 weeks.

No within- or between-group differences reported.

### Cardiometabolic markers
Status: mixed
The PCOS non-exercise group unexpectedly improved body weight, BMI, systolic BP, HDL, insulin, and HOMA-IR, limiting interpretation of HIIT effects.

PCOS Non-Ex body weight and BMI p<0.001; systolic BP p=0.001; HDL p=0.010; insulin p=0.026; HOMA-IR p=0.032.

## Practical Insights

- HIIT did not clearly improve cardiovascular risk markers in this PCOS analysis beyond resting heart rate.
- Low adherence can dilute expected HIIT effects; app programs need adherence support and realistic schedules.
- Lifestyle changes in control groups can strongly affect exercise-study interpretation.

## Limitations

- Secondary outcome analysis not powered specifically for these vascular outcomes.
- Low sample size for FMD and IMT subgroups.
- Suboptimal adherence to prescribed HIIT protocols.
- Control-group lifestyle changes limited between-group inference.
- Some exercise training data were missing because sessions were not registered in Polar Flow.

## Safety And Adherence

- Ten participants dropped out and five became pregnant during the intervention period and were excluded from analysis.
- No exercise adverse events were described in the extracted text.
- Participants were screened to exclude cardiovascular disease and other endocrine disorders.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35329952/) (pubmed)
- [DOI](https://doi.org/10.3390/jcm11061626) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8953804/) (full text)

## Agent Guidance

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