How eating more might improve your exercise performance – BBC
Under-fuelling is when your total energy intake isn’t enough to meet your needs and perform your best. McGregor says it most commonly refers to not having enough carbohydrates – the nutrient that’s regarded as ‘fuel for fitness’.
Despite following a ‘healthy’ diet and making sure she didn’t cut out any major nutrients, Davis was a victim of this.
While Davis was eating normal, everyday meals, fitting in intense early morning training around long hospital shifts made it hard to prioritise the extra nutrients and energy she needed. Sporadic breaks also made it hard to know when her next snack or meal might be.
“I’d be tired from rushing around and quite often train before breakfast… It wouldn’t be clear when I’d get a break when working on the [hospital] ward or if I’d even get to have a break.”
This led to Davis suffering with recurrent stress fractures, tiredness and a decrease in her performance. She was then diagnosed with the serious medical condition RED-S (Relative Energy Deficiency in sport).
“RED-S is when there’s not enough energy to support all movement and biological processes, says McGregor, before adding: “It’s further impacted by internal stress on the body. Stress can be not fuelling enough, losing weight rapidly, training at too high intensity with little or poor recovery” explains McGregor.
It can also lead to other health issues: “It can impact your red blood cell production, so often we will see low iron levels in individuals who are in RED-S,” says McGregor.
Under-fuelling can also affect hormone levels. “Under-fuelling can lead to disruptions in female hormones which can lead to irregular or even loss of periods. If you don’t have regular menstrual cycles, this starts to have a negative impact on other areas of your health and can lead to injuries such as stress fractures.”
Davis describes how losing your period was historically considered the norm in elite athletes, “it used to be seen that if you lost your period, it meant you’re training hard. Now, we know, losing your period is a key sign of under-fuelling. It’s a sign you need to pull back and your body is under stress.”
