Murray said he lost too much weight in the heat
Andy Murray has admitted to being "unprofessional" in the build-up to his short-lived Olympic campaign.
He made the comments after following up his first-round singles loss by losing in the doubles with brother Jamie to Arnaud Clement and Michael Llodra.
"I found out the day after my singles match I'd lost four and a half kilos since I arrived here," he said.
"I didn't prepare as well as I should have done. It was unprofessional and something I need to learn from."
In the run-up to Beijing Murray won his first Masters Series event, in Cincinnati, then flew back to London before flying to China.
He will be keen to put the mistakes of Beijing behind him when the ATP tour resumes with the US Open which starts on 25 August.
"I'll have to make sure it doesn't happen again because I think I'm playing really well right now, the US Open is my favourite tournament and I believe I can do really well there," he said.
"Ideally I'd have like to have got here earlier but I didn't because I played very well in Cincinnati.
"Normally at each tournament I weigh myself right at the start and I should have checked that as soon as I got here instead of the day after my match."
He also admitted that he and his brother had disappointed as a doubles pairing, and would avoid making the same mistake in London in four years time.
"We didn't serve particularly well or return well and it was always going to be difficult if you can't put any pressure on them," he said.
"After being a part of the Olympics for the first time and seeing what it means when the athletes win medals and how big a deal it is you realise how much you want to do well and sometimes you want it a bit too much and don't play so well.
"Next time we will be playing at home on one of our best surfaces and will have a lot more experience."