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

INTRODUCTION: polycystic ovary syndrome (PCOS) is associated with cardiovascular disease (CVD) risk factors. First-line therapy for PCOS is lifestyle changes including exercise. We compared CVD risk factors between women with and without PCOS and examined the responses to high-intensity interval training (HIIT). METHODS: women with PCOS were randomized to HIIT (n = 41) or a non-exercise control group (n = 23) for 16 weeks. Women without PCOS (n = 15) were age- and BMI-matched to participants with PCOS and completed 16 weeks of HIIT. CVD markers included blood pressure, heart rate, flow mediated dilatation (FMD), carotid intima-media thickness (IMT), and circulating concentrations of lipids, glucose, insulin, and matrix metalloproteinase-9 (MMP-9). RESULTS: resting heart rate was higher in women with PCOS than without PCOS (p =0.011) and was reduced after HIIT in women with PCOS (-2.8 beats/min, 95% CI: -5.4, -0.2, p = 0.037). FMD was not significantly different between women with PCOS (5.5%, SD 4.1) and those without PCOS (8.2%, SD 3.9) at baseline. HIIT reduced time-to-peak dilatation of the brachial artery in women with PCOS compared with women without PCOS (-55 s, 95% CI: -96, -13, p = 0.012). CONCLUSIONS: we found little difference in CVD risk factors between women with and without PCOS at baseline, but some indications of endothelial dysfunction in women with PCOS.

Absent Exercise-Induced Improvements in Fat Oxidation in Women With Polycystic Ovary Syndrome After High-Intensity Interval Training.

Background: Polycystic ovary syndrome (PCOS) and metabolic inflexibility are linked to insulin resistance, and women with PCOS appear to be metabolic inflexible in the rested, insulin-stimulated state. Exercise training is a primary lifestyle intervention in PCOS. Exercise training improves whole-body fat oxidation during submaximal exercise in healthy women, yet little is known about the effect on this outcome in women with PCOS. Methods: We measured whole-body fat oxidation rates during sub maximal exercise before and after 16 weeks of high-intensity interval training (HIT) in women with PCOS randomly allocated to either: low- or high-volume HIT (n = 41; low-volume HIT, 10 × 1 min work bouts at maximal, sustainable intensity and high-volume HIT, 4 × 4 min work bouts at 90-95% of maximal heart rate) or non-exercise control (n = 23), and in women without PCOS (Non-PCOS) allocated to low- or high volume HIT (n = 15). HIT was undertaken three times weekly. In a subset of women with and without PCOS, we measured mitochondrial respiration in abdominal and gluteal subcutaneous adipose tissue using high-resolution respirometry, as well as fat cell sizes in these tissues. Results: At baseline, women with PCOS had lower whole-body fat oxidation and mitochondrial respiration rates in abdominal adipose tissue compared to Non-PCOS. Peak oxygen uptake (mL/min/kg) increased in women with PCOS (~4%, p = 0.006) and Non-PCOS (~6%, p = 0.003) after 16 weeks of HIT. Whole-body fat oxidation only improved in Non-PCOS after HIT. No changes were observed in mitochondrial respiration and cell size in abdominal and gluteal adipose tissue after HIT in either group of women. Conclusion: We observed exercise-induced improvements in whole-body fat oxidation during submaximal exercise in Non-PCOS, but not in women with PCOS, after 16 weeks of HIT, suggesting metabolic inflexibility in women with PCOS. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT02419482 and NCT02943291.

Improving reproductive function in women with polycystic ovary syndrome with high-intensity interval training (IMPROV-IT): study protocol for a two-centre, three-armed randomised controlled trial.

INTRODUCTION: Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age and the leading cause of anovulatory infertility. Women with PCOS have a 15-fold higher prevalence of infertility, compared with women without PCOS, independent of body mass index (BMI). A healthy lifestyle is recommended to improve overall health and fertility in PCOS but there is limited evidence on the isolated effects of exercise, especially for reproductive outcomes. Previous findings indicate superior metabolic health benefits after vigorous compared with moderate-intensity exercise. Our primary aim is to determine the effect of high-intensity interval training (HIT) on menstrual frequency, as a proxy of reproductive function, in women with PCOS. METHODS AND ANALYSIS: The study is a two-centre, randomised, controlled trial with three parallel groups. Women (n=64) from Trondheim (Norway) and Melbourne (Australia) with PCOS according to the Rotterdam criteria will be randomly allocated (1:1:1) to high-volume HIT, low-volume HIT or a control group with no exercise after stratifying for BMI < or ≥ 27 kg/m2 and study centre. Measurements for study end points will be undertaken at baseline, after a 16 week exercise intervention and at 12 months following baseline assessments. The primary outcome measure is menstruation frequency, measured as the number of self-reported menstrual bleedings divided by the number of expected menstrual bleedings during a 12-month period. Secondary outcome measurements include markers of cardiovascular, metabolic and reproductive health, as well as quality of life and adherence to and enjoyment of exercise. ETHICS AND DISSEMINATION: The Regional Committee Medical Research Ethics, Norway, and The Australian Catholic University Human Research Ethics Committee, Australia, have approved the trial protocol. This trial will provide new insight regarding the impact of exercise on fertility in PCOS. We expect this trial to contribute to new therapeutic exercise strategies as part of clinical care for women with PCOS. TRIAL REGISTRATION NUMBER: Clinical trial gov NCT02419482.

Women undergoing assisted fertilisation and high-intensity interval training: a pilot randomised controlled trial.

OBJECTIVES: Overweight and obese women often seek assisted fertilisation. In the obese population, pregnancy rates are 30%-75% below that of normal weight women who undergo assisted fertilisation. We hypothesised that high-intensity interval training (HIT) would improve fertility by improving insulin sensitivity and thus affect the hypothalamic-pituitary-ovarian axis and ovarian androgen production. Our aim was to assess whether HIT prior to assisted fertilisation would increase pregnancy rate. METHODS: Eighteen overweight and obese women (body mass index>25.0 kg/m2) were randomised to HIT (n=8) or usual care (control, n=10) before assisted fertilisation. HIT was undertaken three times weekly for 10 weeks; two sessions of 4×4 min HIT and one session of 10×1 min HIT. Primary outcome was ongoing pregnancy. Secondary outcomes included insulin sensitivity, reproductive hormones, oxygen uptake and body composition. RESULTS: Four women got pregnant in both the HIT group (50%) and in the control group (44%), no between-group difference (p=0.6). Insulin sensitivity (glucose infusion rate) improved significantly after HIT, from 264.1 mg/m2/min (95% CI 193.9 to 334.4) at baseline to 324.7 mg/m2/min (95% CI 247.2 to 402.2) after 10 weeks (between-group difference, p=0.04). Fasting glucose, visceral fat, waist circumference and VO2peak were significantly improved in the group that undertook HIT. CONCLUSIONS: HIT significantly improved insulin sensitivity, VO2peak and abdominal fat. Low statistical power makes it difficult to conclude on whether HIT prior to assisted fertilisation could increase pregnancy rate. Larger trials are needed to determine if improvements in insulin sensitivity are clinically relevant for assisted fertilisation success rates in this population.