The former England rugby captain Lewis Moody was used to some tough battles on the pitch but none were to prove harder than coping with a bowel disease.
Ulcerative Colitis is a long-term inflammatory disorder that causes ulceration of the rectum and the colon.
When symptoms of the condition - which can mean bloody diarrhoea, abdominal pain, a frequent need to go to the toilet and weight loss - first appeared, the rugby star put off going to the doctor for four weeks.
It was very debilitating and humiliating as a young man because you expect it to be an old person's disease
Then once he was diagnosed he feared it would wreck his rugby career.
So he hid it from his teammates - but the frequent need to visit the toilet was not always an easy thing to conceal.
"That was really tough to be fair. I don't know anyone that openly talks about their toilet habits.
"So for a young man - I was 25 at the time - all of a sudden you are going to the loo 20 or 30 times a day.
"You are losing a relentless amount of blood and being a classic bloke I left it a month before I went to see the doctor even though this was a daily routine," he told the BBC's HARDtalk programme.
Moody, known affectionately by teammates and fans as "Mad Dog" retired from rugby in March following a shoulder injury.
1996: Makes his senior debut at Leicester Tigers at 18 while still at school
2001: Makes his debut for England against Canada
2003: Part of England's Grand Slam-winning Six Nations squad
2005: Wins three caps for the British & Irish Lions on their tour of New Zealand
2010: Captains England for the first time in a Six Nations clash with France. Leaves Leicester after 14 seasons to join Bath
2012: Announces retirement from rugby after a shoulder injury
He is now supporting the work of the charity Crohn's and Colitis UK and urging other sufferers to get treatment quickly and to try to lift the taboo surrounding the subject.
He said: "It was very debilitating and humiliating as a young man because you expect it to be an old person's disease but it is the complete opposite I have learnt since - most people are diagnosed under the age of 30."
Doctors say the most vulnerable age groups for the disease are those aged between 15 and 30.
"For me not having any information was the hardest thing and trying to hide it from my teammates.
"I had such an array of injuries I didn't want there to be another reason for the guys to say 'well we are not going to be able to pick Lewis because he will never make it to the start of the game because he might have to run off the loo'."
Covering the short distance from his home to training ground could be a battle in itself.
He recalled: "I was struggling to leave the house sometimes. I only lived four minutes away from the training ground and sometimes I would have to plan my route so that I could stop three or four times en route just to go to the loo.
"Some of the poor people in the establishments on the way probably wondered what on earth was going on as I pulled in every morning."
Moody wrote in his autobiography that he believed his rugby career could have played a part in him developing the condition.
He was plagued by injuries throughout his 15 years at the top and this led to an over-exposure to anti-inflammatories, antibiotics and painkillers.
To keep the disease under control he now takes tablets daily and has to stick to a special diet.
Being more open about his condition eventually made it easier to cope with.
"I have to admit it was probably a couple of years until I told my good mates and they probably knew anyway because it was obvious. I had lost weight. I was gaunt.
"But it became much easier when I did tell the guys...
"That was one of the learning curves for me with the disease. The more I spoke about it, the easier it became."
HARDtalk is broadcast on the BBC News Channel and on BBC World News.
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