German swimmers have been instructed not to eat food beyond that provided by the team hotel in Shanghai during the world championships from July 24 to 31, while team doctors will work with hotel chefs to determine the chain of supply. Those moves, in common with action being taken by a number of other leading national teams, follows a series of positive tests for the steroid Clenbuterol by athletes who had visited Shanghai, It is believed that the substance is used illegally in China as a way of beefing up beef and other livestock ready for market. 

Reports in Germany note that FINA will "check the food preparation" in team hotels. It is not, of course, the preparation that is the problem. The source of the meat is the issue - and that is what will need to be checked. Once in the food chain, Clenbuterol will show up in any tests taken on human in the fight against doping in sport. 

Lutz Buschkow, performance director for Germany, told reporters that there would be no ban on meat-eating but precautions would be taken. "A steak is part of it [the life of a sportsman]. I cannot tell Paul Biedermann 'be a vegetarian but swim a world record'." The point is well understood, though worth noting that the great Murray Rose (AUS) was among a fair few vegetarians who broke world records in their time (and the reason why world records might stand in Shanghai is entirely to do with suits not steaks. of course).

Buschkow has called on WADA for some sort of limit to be placed on pursuing action against those who consume products containing clenbuterol through no fault of their own. Table tennis player Dimitrij Ovtcharov tested positive for Clenbuterol last year and was acquitted after it was believed that he had eaten contaminated meat in Shanghai. Of 28 European cyclists tested on return from China recently, 22 tested positive for clenbuterol. 

And there is the rub: the presumption of innocence is, rightly, assumed, however, cheats have long known that to be the case and will exploit it to the maximum. Hard to place a limit on things without creating loopholes in an anti-doping system that sometimes has the feel of a Swiss cheese about it. Teams have spotted the best way to go in Shanghai next month: control, knowledge of food chain and spot testing of the meat that is ending up on the plates of athletes.