Introduction

Recognised as the leading cause of anovulatory infertility, Polycystic Ovary Syndrome (PCOS) affects between 12-18% of reproductive aged women (1). PCOS is a complex disorder with complications extending beyond infertility to include metabolic and psychological manifestations.

Diagnosis requires at least two of the following characteristics; clinical or biochemical hyperandrogenism, anovulatory menstrual dysfunction and polycystic ovaries on ultrasound, in the absence of secondary causes. Although not required for diagnosis, insulin resistance is strongly implicated in the aetiology of PCOS underpinning both reproductive and cardiometabolic disturbances and is present independent of obesity.

Obesity affects 30% of women with PCOS and increases complications (2, 3). Lifestyle change with or without weight loss improves clinical features, including insulin resistance. For this reason, lifestyle modification, incorporating exercise, remains the first line treatment for PCOS.

Exercise, Diet or Combined Lifestyle Change

Diet and exercise alone or in combination have been shown to improve health outcomes in PCOS and therefore ideally they should be used together as part of a healthy lifestyle program to prevent weight gain in all those with a body mass index ≥20kg/m2 and for weight loss in those who are overweight.

When combined with dietary intervention, exercise has been shown to potentiate the effects of diet on reproductive and metabolic outcomes. Alone, exercise therapy has also been shown to improve reproductive and metabolic features independent of change in diet and without any change in weight (4).

Maintaining a specific diet is difficult for many women over time and recent evidence suggests that caloric restriction appears to be more effective in reducing weight and improving clinical features in PCOS than modifying specific macronutrient content (i.e. increased protein, reduced carbohydrate or low glycaemic index etc).

Therefore, a healthy lifestyle incorporating a low fat diet and regular exercise should be promoted.

Reproductive and metabolic health

Previous research incorporating regular exercise at least three times per week (30-60 minutes) for three to six months duration has been effective in improving reproductive features including menstrual regularity and ovulation rate (5, 6).

Results from a six month study reported significantly higher menses frequency and cumulative ovulation rate following exercise in comparison to a low-caloric, high-protein diet alone (5) further highlighting the importance of exercise therapy in PCOS. This research also reported a higher pregnancy rate with exercise (35% compared to 10% with diet).

The most consistent metabolic improvement with regular exercise in PCOS appears to be insulin resistance with either neutral or small changes noted to weight, body fat, waist-to-hip ratio, triglycerides and blood pressure. With insulin resistance underlying many of the complications in PCOS and impacting on progression to complications including type 2 diabetes, improvement is an important target for long-term health and should be emphasised to women with PCOS.

Type of exercise

Previous research has incorporated a variety of exercise interventions in PCOS and most have been effective in improving clinical features regardless of type including moderate or vigorous aerobic exercise or resistance (weight bearing) exercise. Many women, including those with PCOS, may believe they need to partake in a variety of different exercise programs in order to achieve benefits. While variety is beneficial for motivation, it is not essential, and can include simple exercises such as walking for moderate activity. Intermittent vigorous activity is also recommended. The key to maintaining health benefits is ensuring sustainability of exercise over time and setting realistic goals.

Key recommendations

The recently released Evidence Based Guideline for the Assessment and Management of PCOS available via the website: www.managingpcos.org.au/pcos-evidence-based-guideline and also in the September edition of Medical Journal of Australia, evaluates exercise in PCOS and provides health professionals with key exercise recommendations for women. Essentially, the recommendation is to exercise for at least 150 minutes per week (e.g. five, 30 minute sessions), and at least 90 minutes of this should incorporate moderate to vigorous aerobic activity (60-90% of maximum heart rate).

It is important to share with women that this degree of exercise assists in the prevention of weight gain but may not induce weight loss. Women should be encouraged to understand that the health benefits of exercise far exceed those of weight management to optimise motivation and sustainability. 

Talking Women Exercise in PCOS185.47 KB

References

1. March WA, et al. The prevalence of polycystic ovary syndrome in a community sample assessed under contrasting diagnostic criteria. Human Reproduction. 2010; 25: 544-551.

2.  Kiddy DS et al. Differences in Clinical and Endocrine Features between Obese and Non-Obese Subjects with Polycystic Ovary Syndrome - an Analysis of 263 Consecutive Cases. Clinical Endocrinology. 1990; 32: 213-220.

3. Balen A et al. Polycystic ovary syndrome: the spectrum of the disorder in 1741 patients. Human Reproduction. 1995; 10: 2107-11.

4. Harrison CL et al . Exercise therapy in polycystic ovary syndrome: a systematic review. Human Reproduction Update. 2010; 17: 171-183.

5. Palomba S et al. Structured exercise training programme versus hypocaloric hyperproteic diet in obese polycystic ovary syndrome patients with anovulatory infertility: a 24-week pilot study. Human Reproduction. 2008; 23: 642-50.

6. Thomson RL, et al. The effect of a hypocaloric diet with and without exercise training on body composition, cardiometabolic risk profile, and reproductive function in overweight and obese women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2008; 93: 3373-3380.

Content updated 7 November 2011