High intensity intermittent training in Polycystic Ovary Syndrome: A randomised control trial to evaluate clinical and mechanistic improvements in metabolic health.

Women will be randomized into the control and 2 exercise intervention groups. Prior to the exercise intervention phase women in both groups will undertake a behavioural lifestyle intervention: an adapted, evidence-based lifestyle behavioural intervention will be provided to all participants to i) ensure exercise is provided in context of combined behavioural and dietary intervention as per guideline recommendations ii) to optimise retention, engagement, motivation and sustainability of exercise. This program and includes provision of healthy eating advice and health promotion behaviour change principles resulting in improved retention (~10% attrition rates in 3 large prior RCT’s compared to standard ~30% dropout rates). This involves 3 x 1 hour group sessions (1 session per week over 3 weeks) focused on diet information and behavioural modification techniques based on social cognitive theory including goal setting, self-monitoring, social support, coping strategies, problem solving and relapse prevention . Non-prescriptive and non-individualised dietary advice is provided consistent with the Australian Dietary and Healthy Eating Guidelines with a focus on healthy food choices, reducing intake of energy-dense and non-core foods and increasing intake of low energy-dense foods. These sessions encourage physical activity (low intensity exercise for 150 minutes/week) but do not include structured exercise. Lifestyle sessions will be provided by trained exercise physiologists. Exercise interventions (24 weeks): All exercise sessions will be undertaken on cycle ergometers at either Monash University, Victoria University or University of South Australia fitness centres under the supervision of exercise physiologists, who have trained hundreds of overweight & PCOS women. The standard exercise (SE) intervention group is designed to meet the Australian National Physical Activity guidelines of 150 min of exercise per week, while the high-intensity interval exercise group (HIIE) will be matched for weekly energy expenditure. Standard exercise group(SE)- In addition to behavioural intervention participants will perform 3 supervised low-moderate intensity cycling sessions of 50 minutes at 65-75% of maximal aerobic exercise capacity (using heart rates) per week. This is based on current national and international physical activity guidelines. Exercise sessions will be progressed and adjusted fortnightly to account for individuals exercise capacity and training adaptations. High intensity intermittent group (HIIE; energy expenditure equivalent to SE-exercise group): In addition to behavioural intervention participants will perform 3 sessions of supervised HIIE cycling sessions/ week. The HIIE sessions entails completing 8-12 x 1min bouts of exercise at 95-100% maximal aerobic capacity (using heart rate) with 1min recovery. HIIE cycling sessions will be progressed and adjusted according to individual capabilities to prevent injury and account for training adaptations. . Isocaloric balance of HIIE and SE interventions: With cycle ergometry we can determine work done (energy expended)/session and which we will compliment energy expenditure determined from heart rate monitors (Polar [Trademark]) and accelerometers to match work done between groups.