The Rugby Football Union is commissioning a unique study into how the performance of female rugby players is affected by different stages of their menstrual cycle.

This is believed to be some of the first research of its kind and could provide information as to whether planning training around menstrual cycles helps elite rugby players maximise their performance and reduce risk for injury.

The study is being led by Omar Heyward, a women’s pathway strength and conditioning coach for England Rugby and a PhD scholar at Leeds Beckett University, reports the Telegraph.

Discussions around the link between a woman's menstrual cycle and sport have been highlighted over the last few weeks after Chelsea Football club and the England Lionesses revealed they will be monitoring cycles in order to maximise performance and minimise injury.

The predictions:

Heyward is looking at the fat to carb intake ratio athletes require at different phases and the influence of both progesterone and oestrogen levels on performance.

He said: “When oestrogen levels are very low a woman is bleeding. Women often report cramping and other symptoms associated with menstruation. 

"That’s where the variability in symptoms becomes a really important factor. Some women have no or very limited symptoms. Others experience symptoms which can have a really negative effect. 

"It’s not as simple as looking at what the hormone levels are like. There’s also no strong body of evidence around what women should be eating around certain phases of their menstrual cycle. The research just isn’t there yet.”

The process:

20 rugby players will undergo a repeated ‘Wingate Test’ to investigate anaerobic (without oxygen) leg power by sprinting for 30 second bursts on a Watt bike.

They will repeat the sprint three times with a recovery rest between each, at three phases of their cycle (early follicular, late follicular and mid luteal phases) to investigate the link between hormone levels and performance.

Early follicular phase - First four days of a woman's cycle when the woman is bleeding. At this time both oestrogen and progesterone levels are low and women may experience bloating and cramps.

Late follicular phase - Mid-cycle around day 14 of a 28-day cycle. The egg is released and oestrogen levels reach their highest point of the cycle while progesterone levels also increase. Women are expected to draw on fat for energy during high intensity exercise.

Mid luteal phase - Approximately seven to nine days following ovulation where the body makes preparations for pregnancy. Progesterone levels peak and then drop.

Female players aged between 16 and 40 are invited to take part and must not be on any form of hormonal contraception or have any menstrual difficulties such as Polycystic Ovarian Syndrome.

Heyward finished by adding: “It’s important that coaches and practitioners start tracking menstrual cycles.

“Are we fitness testing players in the same phase of the cycle? 

“If a woman is doing a fitness test in her early follicular phase at the start of the season, and then does the same test mid-season in a different phase of the menstrual cycle, that could have an effect on performance.”