St Mary’s Academics Publish Breakthrough Research on Link Between Menstruation and Sport Injury

Professor of Applied Sport and Exercise Science Charles Pedlar and Research Associate Dr Georgie Bruinvels at St Mary’s University, Twickenham (SMU) have collaborated with researchers from University College London (UCL) and University of Bath on research that shows injuries are more likely to occur at certain points in a female athlete’s menstrual cycle than others. The research has been published in the academic journal, Medicine & Science in Sports & Exercise.

The published research is the first prospective longitudinal study monitoring menstrual cycles alongside injuries in female footballers. The research team at SMU, UCL, and the University of Bath found that football players in England’s top-tier, the Women’s Super League (WSL), were six times more likely to experience a muscle injury in the days leading up to their period compared to when they were on their period.

Senior author of the study and Research Associate at SMU and UCL Dr Georgie Bruinvels said, “While these results must be viewed with some caution, the data highlight a need to investigate this area further. Given the growth of women’s sport it’s an exciting time to be working in female physiology, but there are a number of known challenges when conducting research with female athletes, in part explaining why there is such a significant sex data gap.

“Conducting large-scale research is complex but must be prioritised to best support female athletes, and we hope studies like this will pave the way for this. Every woman has their own unique physiology, so it’s crucial to support and empower them in the right ways. If future research demonstrates that there are risk windows for certain injury types, we should be proactive in mitigating these risks to enable female athletes to exercise and compete on any given day.”

In their study, academics recorded time-loss injuries and menstrual cycle data for elite female football players across three seasons at a WSL club. This involved tracking 593 cycles across 13,390 days, in which 26 players experienced 74 injuries.

Professor Charles Pedlar added, “Although this is a small study it has strength in the quality of the athletes and the duration of the monitoring. It demonstrates the potential importance of collecting menstrual cycle data alongside female athlete injury data in all studies of this kind going forwards.”

The researchers divided each cycle into four main phases with different assumed hormonal changes. These in turn have the potential to affect different aspects of a woman’s health and wellbeing. The four phases include:

• Menstruation when reproductive hormones are low.
• Mid-to late follicular phase when oestrogen is assumed to be increasing.
• Early-mid luteal phase after ovulation when both oestrogen and progesterone are assumed to increase and remain high.
• Pre-menstrual phase where oestrogen and progesterone decrease to bring about the onset of menstruation.

Analysis of the data found that players were six times more likely to experience a muscle injury in the pre-menstrual phase and five times more likely to in the early-mid luteal phase, compared to when they were in the menstrual phase.

The results from this small sample size demonstrate the need to consider the effects of the menstrual cycle in elite sports, leading to a reduced injury risk and better wellbeing support for athletes.