It becomes tricky, and you start to think about the cramps rather than just actually what you're trying to do on the court, which is obviously win the match.
Andy MurrayI guess the closest I came was doing chores around the house to earn pocket money. My brother and I would have to do the washing up, cleaning around the house, walking my grandparents' dog, lots of things. We didn't get a huge amount but it was always enough to be able to walk down to the local shops and get some sweets.
Andy Murray