"If you keep this up, you'll be in a wheelchair at 30." That is what doctors told British long-distance runner Jake Smith four years ago. From the outside, his career was flying. By the age of 23, he had signed a professional contract with Nike and represented Great Britain on the global stage. But his body was deteriorating, caught in a relentless pattern of race, illness, injury, repeat.
Balancing an intense training regime with disordered eating meant the 28-year-old returned from a running camp in Uganda weighing just eight stone (51kg) at 5ft 5in (1.7m). His bones were so brittle that he was told his career could be over. After two stress fractures in four months, Smith sought professional help and was diagnosed with REDs, or relative energy deficiency in sport. The syndrome can affect anyone. If left undiagnosed or untreated, it can harm performance and cause serious, long-lasting health problems.
Women's symptoms are better documented. Last month, tennis player Emma Navarro revealed her diagnosis and her decision to step away from competition until 2027. Men are just as susceptible, but stigma and a lack of obvious warning signs mean the condition can go undetected for longer. REDs can cause bone stress injuries, disrupted sleep, fatigue and low mood. Left untreated, it can lead to osteoporosis, cardiovascular disease and fertility issues. Dr Nicky Keay, an expert in hormone health, says these symptoms stem from hormonal disruption caused by insufficient energy intake.
In women, the menstrual cycle acts as a monthly health check, and REDs can switch periods off. In men, testosterone levels drop, reducing libido and causing fatigue. The International Olympic Committee renamed the condition in 2014 to recognise that it also harms male athletes. A recent meta-analysis found that 49.4% of male athletes and 44.2% of female athletes had low energy availability. One reason for its prevalence is the belief that "lighter is faster" in sports such as endurance running and cycling. For Smith, that belief was where his problems started.
Source: BBC Sport · Summarized by HeadlinesBriefing