Four-time world champion triathlete Lucy Charles-Barclay has opened up about the shocking discovery that transformed her health and her racing career. For years, the British endurance star was unknowingly harming her own body while trying to fuel for elite Ironman events — all because she didn’t know she had coeliac disease.

The 32-year-old, known for her intense training schedule of 30 hours per week and indoor bike sessions lasting up to six hours, assumed her issues were simply part of the sport. But constant fatigue, repeated stress fractures, and unexplained injuries eventually pushed her to search for answers.

Everything changed in 2024 when Charles-Barclay learned she had coeliac disease — an autoimmune condition where eating gluten triggers the immune system to attack the small intestine.

That meant the pasta and bread she relied on for energy during heavy training were actually hurting her.

“I was trying to carb-load with foods like pasta and pizza,” she told BBC Sport. “But instead of fuelling myself, I was basically poisoning my body before these huge endurance events.”

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Carb-Loading Gone Wrong: When Pasta Hurts Performance

For endurance athletes, carbohydrate loading is essential. Ironman and triathlon competitors need massive amounts of energy to race in extreme heat, humidity, and over long distances. A Half Ironman, for example, includes a 1.2-mile swim, a 56-mile bike ride, and a half-marathon.

But for people with coeliac disease, many traditional carb sources — such as pasta, bread, and cereals — are off-limits.

Charles-Barclay’s performance in early 2024, including opening her season in Singapore’s extreme heat, made fuelling even more important. Yet the very foods she depended on were making her weaker.

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Injuries That Didn’t Add Up: The “Lightbulb Moment”

Before her diagnosis, Charles-Barclay endured a long list of physical setbacks:

• A broken foot mid-race
• Two stress fractures
• Two calf muscle tears

Despite working closely with coaches and medical staff, nobody could pinpoint the root cause.

“Consuming gluten for 30 years without knowing you’re coeliac causes a lot of damage,” she said.
“When I finally got the diagnosis, it was a massive lightbulb moment.”

Because her body couldn’t properly absorb nutrients, she became more vulnerable to injury, low energy, and poor recovery.

For Charles-Barclay, the diagnosis wasn’t upsetting — it was empowering.

“For me, finding out was positive. It explained everything.”

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The Challenge of Going Gluten-Free

Transitioning to a gluten-free diet was far from easy. Many everyday carbohydrate foods — including some sports supplements — contain hidden gluten. And gluten-free replacements are typically more expensive. A Coeliac UK report found affected individuals spend 35% more on groceries per week.

Charles-Barclay also experiences symptoms like headaches, bloating, and stomach pain when she accidentally consumes gluten, so staying vigilant is key.

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New Race Fuel: Gluten-Free Carb-Loading and Hydration

It took about a year for her small intestine to fully heal. Now, her fuelling routine is completely different:

Three days before a race:

• Multiple bowls of rice
• Chicken
• Boiled eggs

During the race:

• Gluten-free gels
• Up to 120g of carbs per hour
• Extra electrolytes from salt tablets
• Additional energy from Red Bull

“By the time race day comes, I don’t want to see rice again for a long time,” she joked.

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Eyes on the T100 Triathlon World Championship

Charles-Barclay is now preparing for the T100 Triathlon World Championship finale in Qatar on 12 December. She sits just nine points behind the leaders — Canada’s Julie Derron and Britain’s Katie Waugh — and remains a strong favourite thanks to her revitalised fuelling strategy.

“It’s going to be hot and tough, but exciting. And now I know exactly how to fuel properly.”

Her journey highlights the importance of proper nutrition, early diagnosis, and listening to your body — even when you’re one of the best athletes in the world.