RUNNING ON EMPTY

Training hard? Under-fuelling? There’s more at stake than a couple of off days – including your health. Here’s what you should know about the condition known as Red-S

Words by Joel Snape

READING RED-S

In 2021, upcoming distance runner Jake Liam Smith was training in Uganda, when some of the world’s best athletes took him to one side for a chat. ‘Joshua Cheptegei, the world record holder in the 10K, and Jacob Kiplimo, the half marathon record holder, came up to me and said, “Jake, you look too skinny,”’ he says. ‘I made a joke of it at first – I’d been eating less meat while I was out there, and training hard – but really, they were right. I was a 23-year-old man who weighed 51kg. The last day I was out there, I could not physically run uphill, I just had nothing in the tank. I got back home and we did some tests. It turned out that I was anaemic and had signs of osteoporosis in my bones. The consultants said to me, “If you keep running at this intensity while you’re under-fuelling, you’ll probably be in a wheelchair at 30.”’

Jake eventually found out that he was suffering from Red-S, or relative energy deficiency in sport – a condition that typically occurs when energy intake doesn’t meet the demands of the activity an athlete is undertaking. First described by the International Olympic Committee (IOC) in 2014, it can be a life-threatening condition, where non-essential bodily functions start shutting down so that the body can hold on to its limited supplies of fuel. It’s sometimes linked to disordered eating, but it’s possible (and actually relatively common) to experience Red-S while remaining within or even above a ‘healthy’ BMI. And though it’s most common among professional athletes, the rising popularity of ultrarunning events, Ironman triathlons, fitness races and extreme endurance tests means that amateur athletes, who typically have less time and resources to dedicate to optimal nutrition than pros, could be increasingly at risk.