High-intensity training elicits greater improvements in cardio-metabolic and reproductive outcomes than moderate-intensity training in women with polycystic ovary syndrome: a randomized clinical trial

Abstract

STUDY QUESTION Does 12 weeks of high-intensity interval training (HIIT) result in greater improvements in cardio-metabolic and reproductive outcomes compared to standard moderate-intensity continuous training (MICT) in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER HIIT offers greater improvements in aerobic capacity, insulin sensitivity and menstrual cyclicity, and larger reductions in hyperandrogenism compared to MICT. WHAT IS KNOWN ALREADY Exercise training is recognized to improve clinical outcomes in women with PCOS, but little is known about whether HIIT results in greater health outcomes compared to standard MICT. STUDY DESIGN, SIZE, DURATION This was a two-armed randomized clinical trial enrolling a total of 29 overweight women with PCOS between May 2016 and November 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS Women with PCOS aged 18–45 years were randomly assigned to 12 weeks of either MICT (60–75% peak heart rate, N = 14) or HIIT (>90% peak heart rate, N = 15), each completed three times per week. The primary clinical outcomes were aerobic capacity (VO2peak) and insulin sensitivity (euglycaemic–hyperinsulinaemic clamp). Secondary outcomes included hormonal profiles, menstrual cyclicity and body composition. MAIN RESULTS AND THE ROLE OF CHANCE Both HIIT and MICT improved VO2peak (HIIT; Δ 5.8 ± 2.6 ml/kg/min, P < 0.001 and MICT; Δ 3.2 ± 2 ml/kg/min, P < 0.001), however, the HIIT group had a greater improvement in aerobic capacity compared to MICT (β = 2.73 ml/kg/min, P = 0.015). HIIT increased the insulin sensitivity index compared to baseline (Δ 2.3 ± 4.4 AU, P = 0.007) and MICT (β = 0.36 AU, P = 0.030), and caused higher increases in sex hormone-binding globulin compared to MICT (β = 0.25 nmol/l, P = 0.002). HIIT participants were 7.8 times more likely to report improved menstrual cyclicity than those in the MICT group (odds ratio 7.8, P = 0.04). LIMITATIONS, REASONS FOR CAUTION This study has a small sample size and the findings of the effect of the exercise interventions are limited to overweight reproductive-aged women, who do not have any co-existing co-morbidities that require medication. WIDER IMPLICATIONS OF THE FINDINGS Exercise, regardless of intensity, has clear health benefits for women with PCOS. HIIT appears to be a more beneficial strategy and should be considered for promoting health and reducing cardio-metabolic risk in overweight women with PCOS. STUDY FUNDING/COMPETING INTEREST(s) This work was supported by a Project Support Grant from the Australian National Health and Medical Research Council (NHMRC) Centre for Research Excellence in PCOS. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER ACTRN12615000242527. TRIAL REGISTRATION DATE 19 February 2015. DATE OF FIRST PATIENT’S ENROLMENT 27 May 2016.

Transforming growth factor β1 impairs the transcriptomic response to contraction in myotubes from women with polycystic ovary syndrome

“…All clinical measures and testing, including body composition assessment by dual energy X‐ray absorptiometry (DXA) scan (iDXA GE Lunar Prodigy scanner; GE Healthcare, Milwaukee, WI, USA) and euglycaemic–hyperinsulinaemic clamps to assess insulin sensitivity were conducted after an overnight fast and in the early follicular phase of the menstrual cycle (days 1–7) for those participants with regular menstrual cycles, following the methods previously described (Moreno‐Asso et al., 2022). Cardiorespiratory fitness level ($${\dot{V}_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$$) of all participants was assessed as previously described (Patten et al., 2022).…”

Insulin resistance in polycystic ovary syndrome across various tissues: an updated review of pathogenesis, evaluation, and treatment

“…There have been conflicting conclusions regarding the efficacy of the choice of optimal exercise mode in improving insulin sensitivity in women with PCOS. The heterogeneity of PCOS necessitates individualization of treatment options, and it appears that exercise combined with additional dietary/drug intervention is better for improving insulin sensitivity than either intervention alone [149][150][151].…”

Efficacy of high-intensity interval training for improving mental health and health-related quality of life in women with polycystic ovary syndrome

“…Body mass index (BMI) was calculated as weight[kg]/height squared[m]. Additional body composition measures were collected and reported in Patten et al 37 .…”

“…The initial three stages of the test consisted of three 3 min stages of cycling at 25, 50 and 75 watts, respectively, followed by increases of 25 watts each minute thereafter until volitional exhaustion. Breath-by-breath expired respiratory gases were collected and analysed (Quark Cardio-Pulmonary Exercise Testing, Cosmed, Italy) and relative VO 2peak was calculated as previously described 37 . Peak heart rate (HR peak ) was also recorded (Polar H10, Polar Electro OY, Kempele, Finland) in order to determine exercise training intensities.…”

“…Insulin sensitivity. Insulin sensitivity was assessed using the euglycaemic-hyperinsulinaemic clamp described in Patten et al 37 . In brief, a bolus of insulin of 9 mU/kg was infused, followed by a constant insulin infusion rate of 40 mU/min/m 2 with glucose (20%) infused at a variable rate to meet the target blood glucose of 5 mmol/L.…”