CN: this article contains discussion of eating disorders

Mary Cain, often described as the ”fastest girl in her generation“, spent much of her school years running at a national and international level. With a glowing career in athletics beckoning, Cain joined the Nike Oregon Project in 2013 at the young age of 17. The same year, she was the youngest American track and field athlete to make a World Championships team. The success didn’t last forever, and things started to go wrong within just two years. Articles at the time scrutinised everything from her bodyweight, to her inability to transition from life at home to life at college, to a lack of confidence. The truth? Cain was partway through a battle that led to broken bones, an absence of her menstrual period for years, and extremely low energy.

The female athlete triad, sitting within the broader classification of Relative Energy Deficiency in Sport (RED-S) is a syndrome characterised by three key hallmarks: decreased bone mineral density, amenorrhoea/oligomenorrhoea (loss of a menstrual period, or irregular menstruation in those who menstruate) and disordered eating patterns. Essentially, athletes are not eating enough to support their high energy expenditure. There is often some underlying motivation; in the case of Mary Cain, who was set a goal weight by her coaches that she later reflected was far too low to be sustainable or healthy, the idea that a lower bodyweight can correlate with faster running speeds was a likely driver. It is therefore perhaps unsurprising that reports of athletes suffering from RED-S tend to come largely from sports where aesthetics is arguably a focus, such as ballet or gymnastics.

“Disordered eating patterns in sport are, unfortunately, common”

Disordered eating patterns in sport are, unfortunately, common. Estimates suggest that the incidence may be as high as 6-45% in athletes identifying as female, and up to 19% in athletes identifying as male. The effects of prolonged under-eating can be severe, but will likely initially present with low energy availability that will most likely compromise their sporting success, likely explaining Mary Cain’s slump.

Other effects include abnormal patterns of menstruation. The menstrual cycle and the ovulation within in are governed by the hypothalamic–pituitary–gonadal axis: the signalling relationship between the hypothalamus in the brain, the pituitary gland at its base and the gonads themselves. This is initiated by pulses of gonadotrophin releasing hormone (GnRH) secretion from the hypothalamus, which can be affected by a range of factors – for example, fluctuations in bodyweight due to excessive exercise and/or a restrictive diet can prevent this hypothalamic output. The subsequent lack of secretion of ovarian hormones may lead to a disrupted menstrual cycle. Whilst many athletes experiencing this are likely young and focussing primarily on their careers, a disrupted menstrual cycle over a long period of time does have implications for an individual’s future ability to have children, should they so wish.

Athletes experiencing RED-S frequently suffer stress factors, despite often being clinically underweight. For example, this study investigating the incidence of stress fractures in a relatively small sample size of ballerinas found that the majority of dancers who had suffered recent stress fractures were also underweight, reporting a lower fat intake and a greater focus on low calorie-density foods than a matched control dancer. Osteoporosis is typically seen as a disease affecting primarily elderly women; however low oestrogen levels combined with poor nutrition can mean that broken bones can affect athletes in their supposed prime. One of oestrogen’s many functions is to regulate apoptosis of cells called osteoclasts, which are responsible for bone resorption. If circulating oestrogen concentrations become much lower than physiologically normal levels, osteoclast activity can increase at the expense of bone density. This is especially concerning as bone density for the duration of an individual’s life is thought to peak somewhere between the ages of 18-25 years old, which may well correlate with the ages between which an athlete is putting themselves through an extreme diet to ‘make the most of their prime’, leading to long term damaging effects on bone health.

“On top of the chaotic lifestyle of being an elite athlete at such as young age, Mary Cain had to battle with a coach weighing her in front of other athletes and berating her for the number”

Finally, the psychological effects of RED-S cannot be ignored. Pressure – whether put on an athlete by themselves or by a coach – can be jarring. On top of the chaotic lifestyle of being an elite athlete at such as young age, Mary Cain had to battle with a coach weighing her in front of other athletes and berating her for the number. Cain recalled engaging on a “self-destructive path” upon being told that the reason for her decline in performance was that she was “five pounds too heavy”. Not only was her talent likely compromised by simply having not enough fuel in the tank, her mental and physical health was compromised. She is not the only athlete to be in this position: whether on an international level or simply within a school or university sports team, it is unfortunately far too common for athletes around the globe to have their wellbeing and performance damaged by RED-S.

The world of sport is getting better at taking care of its athletes, but there is still a long way to go. RED-S is well recognised as a serious concern, but is still of alarmingly high prevalence, with many athletes perhaps reluctant to seek help. It is always admirable to push yourself in your chosen field – but athletes, and the support team around them, need to prioritise their physical and mental health.