Effect of Exercise on Ovulation: A Systematic Review

Abstract

Several clear gaps have been identified in the existing literature. Short-term studies of over-training have not always produced the disturbance to ovulation identified in the observational studies, bringing up the question of the roles of longer term training and chronic energy deficit. We believe this merits further investigation in specific cohorts, such as professional athletes. Another gap is the complete absence of exercise-based interventions in anovulatory women with a normal body mass index (BMI). The possibly unjustified focus on weight loss rather than the exercise programme means there is also a lack of studies comparing types of physical activity, intensity and settings. We believe that these gaps are delaying an efficient and effective use of exercise as a therapeutic modality to treat anovulatory infertility.

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

“…The IMPROV-IT trial will determine the effect of HIT on reproductive, cardiovascular, metabolic and psychological health in women with PCOS. The trial will contribute evidence of more specific exercise protocols in the treatment and management of PCOS for clinicians and answer some of the current limitations addressed by both the International evidence-based guidelines for the assessment and management of PCOS4 and several systematic reviews 2 12 25 58. This trial is highly relevant and important as PCOS is a major burden for the women with PCOS, the health services and society.…”

“…Some studies have demonstrated positive effects in reproductive outcomes after exercise, with concomitant improvements in insulin sensitivity and/or visceral fat 20–24. However, more knowledge is needed about the underlying mechanisms for improvement in fertility after exercise training, as discussed in several systematic reviews on lifestyle interventions and fertility 12 25 53 54. HIT has shown to be time efficient, safe and well tolerated, with positive effects on metabolic and cardiovascular risk factors in several studies 29 55 56.…”

“…Exercise training positively affects metabolic, cardiovascular and psychological outcomes in women with PCOS, but the effect on fertility is unclear 4 12 17–19. Some trials20–24 and systematic reviews12 25 report improved ovulation or menstruation frequency after a period of exercise training or after a combined exercise-diet intervention 26. Two of these studies indicate a weight-independent effect of exercise on fertility, suggesting insulin sensitivity to be a key factor 21 23.…”

“…However, 8 weeks follow-up may be too short to determine any effect of exercise training on menstrual frequency. Furthermore, inconsistent reporting of fertility-related outcomes, small sample sizes and short intervention periods, make it difficult to interpret the effect of exercise on fertility 2 4 12 25…”

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

“…There is, however, a lack of good-quality randomised controlled trials comparing types of physical activity, intensity and durations on reproductive outcomes and the focus have been mainly on weight loss. 15 …”