Exercise Training and Reproductive Outcomes in Women With Polycystic Ovary Syndrome

A Pilot Randomized Controlled Trial

Jamie L. Benham; Jane E. Booth; Bernard Corenblum; Steve Doucette; Christine M. Friedenreich; Doreen M. Rabi; Ronald J. Sigal


Clin Endocrinol. 2021;95(2):332-343. 

In This Article

Abstract and Introduction


Objective: Exercise is recommended for polycystic ovary syndrome (PCOS), but the most effective exercise prescription is unclear. This trial compared effects of high-intensity interval training (HIIT), continuous aerobic exercise training (CAET) and no-exercise control on reproductive, anthropometric and cardiometabolic outcomes in PCOS.

Design: Pilot randomized controlled trial.

Participants: Previously inactive women aged 18–40 years with PCOS.

Measurements: Feasibility outcomes included recruitment, retention, adherence to exercise and daily ovulation prediction kit (OPK) testing. Preliminary efficacy outcomes included reproductive, anthropometric and cardiometabolic health markers.

Results: Forty-seven women were randomized to no-exercise control (n = 17), HIIT (n = 16), or CAET (n = 14). Forty (85%) participants completed the trial. Median exercise adherence was 68% (IQR 53%, 86%). Median daily OPK-testing adherence in the first half of the intervention was 87% (IQR 61%, 97%) compared with 65% (IQR 0%, 96%) in the second half. Body mass index decreased significantly in CAET compared with control (−1.0 kg/m2, p = .01) and HIIT (−0.9 kg/m2, p = .04). Mean waist circumference decreased in all groups (−7.3 cm, −6.9 cm, −4.5 cm in HIIT, CAET and control) with no significant between-group differences. Mean LDL-C was significantly reduced for HIIT compared to CAET (−0.33 mmol/L, p = .03). HDL-C increased in HIIT compared with control (0.18 mmol/L, p = .04).

Conclusions: There were feasibility challenges with adherence to daily ovulation assessment limiting the ability to analyse the effect of the exercise interventions on ovulation. CAET and HIIT were both effective at improving anthropometrics and some cardiometabolic health markers. Further studies need to determine optimal and acceptable exercise prescriptions for this population.


Polycystic ovary syndrome (PCOS) affects about 15% of reproductive-aged women[1] and causes significant morbidity. PCOS is characterized by irregular menses, androgen excess and/or polycystic ovaries[2] and is associated with infertility,[3] reduced health-related quality-of-life,[4] and cardiometabolic abnormalities.[5]

Roles of aerobic exercise including continuous aerobic exercise training (CAET)[6,7] and high-intensity interval training (HIIT)[8,9] in PCOS management have been explored. Preliminary evidence suggests aerobic exercise training may improve cardiometabolic and reproductive health in women with PCOS with overweight or obesity,[6–8] but data on reproductive outcomes are inconsistent.[10] Based on these data, clinical practice guidelines recommend diet and exercise for weight loss to treat PCOS in the context of overweight, but the type and dose of exercise are not specified. No previous studies directly compared effects of HIIT versus CAET in women with PCOS. In a non-PCOS trial, HIIT resulted in improved cardiovascular fitness and greater fat loss compared with CAET.[11] HIIT requires less time than CAET.[12,13] Since time is a major barrier to exercise in women with PCOS,[14,15] comparing effects of CAET and HIIT on reproductive sequelae of PCOS is relevant.

This pilot trial was designed to assess feasibility of conducting a full-scale randomized controlled trial (RCT) evaluating effects of HIIT and CAET compared with no-exercise control on ovulatory rate in women with PCOS. To inform planning of future trials, an evaluation of feasibility regarding recruitment, attrition and protocol adherence was required. In particular, the feasibility of daily at-home ovulation assessments in ambulatory reproductive-aged women needed testing. Our other objective was to evaluate the effects of HIIT and CAET compared with no exercise on reproductive, anthropometric and cardiometabolic health markers in women with PCOS.