How to train for triathlon with Crohn’s disease

Elite triathlete Sian Rainsley opens up about her journey from the devastation of her Crohn’s disease diagnosis to becoming an elite athlete at the top of her sport


In 2018, doctors told GB pro triathlete Sian Rainsley that her Crohn’s disease would be the end of her career as an elite sportswoman.

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Four years on, Sian sits at number four on the World Triathlon Championship Series rankings, having broken into the senior ranks with a bronze at the Europe Triathlon Championships in Valencia in 2021, and is in with a chance of making her first Commonwealth Games this year.

Sian was making a name for herself in the junior ranks with a silver at the Nanjing Youth Olympic Games in 2014. But just two years later, her world was to be turned upside down with a diagnosis of Crohn’s.

“At first I had no idea how Crohn’s would impact me,” says Rainsley. “There was a lot of uncertainty in those first few years, but I just battled on with my training. It wasn’t until 2018 when I had a massive flare up that it all really hit home.

“I was hospitalised for a few days with it, and that was when the doctors told me that it would be impossible to continue into elite sport – especially an endurance sport like triathlon.

“It was the lowest point of my life. Without the love and support of friends and family, who knows where I’d be now.”

Sian Rainsley has worked with coaches and dieticians to help manage her condition so she can perform alongside the best in the world (Credit: CSansom)

Sian continued to work with doctors to refine her medication to supress the symptoms of Crohn’s disease – and built up her training to get back into shape.

“It took me a while, but over the next two years I built back my fitness, but more importantly my confidence working with coaches and dieticians that understood my condition,” Sian added.

When Covid hit, Sian’s plans to turn pro were once again delayed. “It was yet another knockback. I honestly wondered if it was ever going to happen. But in 2021 I made the move into the pro senior ranks and have never looked back.”

What is Crohn’s disease?

Crohn’s disease is a type of inflammatory bowel disease (IBD). A lifelong condition which causes inflammation in parts of the digestive system. Around 300,000 people in the UK are known to be living with the disease.

How can Crohn’s disease affect training for triathlon?

As an elite triathlete, Sian must manage her Crohn’s through medication, diet and a flexible training programme.

“When it comes to training and racing, I have to focus on the same things as every elite athlete, just some are more important and need to be adapted for my training.

“I have to be acutely in tune with my body and recognise the signals that can lead to a flare-up. If I’m feeling run down, I can’t just push through it, I need to rest and err on the side of caution.

What can you do to alleviate symptoms of Crohn’s disease when training for triathlon?

“I therefore factor in more sleep, more recovery time, and manage my intensity level more based on how my body is reacting, rather than sticking to a concrete training programme.

“Fuel and hydration are also key. For this I work with a British Triathlon nutritionist to manage my diet and swear by recovery protein shakes.

“Crohn’s can also affect my muscle recovery. I suffer from DOMS to a much greater extent than others. In extreme circumstances I’ve even experienced exertional rhabdomyolysis, or muscle breakdown, where my body uses my muscle as a source of fuel.

“It’s a real balance for my training with flexibility being at the heart of my strategy. I have to push myself, but also be sensible with how hard I go. “

Having broken into the senior ranks with some great results, Sian is looking to consolidate her arrival with more medals this year.

With Super League Triathlon and the World Triathlon Championship Series a focus for her season, she is definitely one to watch.

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To find out more about Crohn’s disease, visit the Crohn’s and Colitis UK charity website.