"We made Sebastian Coe blush at a press conference, bless him," Lisa Power of the Terence Higgins Trust (THT) says. It was 2007, two years after London won the bid to host the Games, still plenty of time to talk about the "no 1 Olympic sport that won't get a gold medal".

The logistics of sexual health are far more complicated than the Olympic lanes, and start years before the athletes arrive. Before any of that, the construction workers arrive.

Power said: "There were a number of articles that suggested that all these foreign workers were going to come in and infect us. We were much more worried about people coming here and getting STIs from our population. In any international event, it's an exchange of risk. Generally people are more at risk in London than they are in wherever they were before. We're the STI capital of Europe."

This misapprehension resolved, there is the fact that a Games, any Games, is good for spreading a safe sex message to the population at large, partly because athletes have really good condom take-up, and partly because of the carnivalesque atmosphere. "That's not just the athletes, that's everybody. There's plenty of research evidence showing that people on holiday are more risky than they are at home. That's whether you're at the Olympics, or in Ibiza, or you would be amazed at the high-risk behaviour that takes place at the World Aids Conference," Powers remarks ruefully.

THT has a good record of using the Games as a way into discussing safe sex, and annoying the International Olympic Committee at the same time (It's really easy, you just have to arrange some condoms to look like the Olympic logo. It makes them livid).

There isn't much research data on athletes or anyone else contracting STIs while they're at a Games – they would not normally be symptomatic until they got home – but, says Powers, "what we do know is there's a huge appetite for condoms in the village". (This was true even in Salt Lake City, the Mormon heartland; and in Sydney, the Olympic village ran out of condoms. Indeed, one of the reasons London started planning so early is that one of the senior members of the health promotion committee had been involved in the "mopping up, as it were, after Sydney".)

Organisers take their responsibilities to the athletes very seriously in this regard, while remaining discreet on the matter of their legendary shagging (on the matter of this legendariness, it was reported that the gay dating app Grindr had crashed after the athletes arrived). Powers says that at the Manchester Commonwealth Games in 2002, they wrapped the condoms in gold, to look like medals. Pam Venning, who co-ordinated the health services for those athletes, and is performing the same job for Locog, said tetchily: "No, we just had ordinary condoms. We had folds of condoms."

Nevertheless, uptake is extremely good. "But they don't have to get the condoms from us, Venning said. "We put them out and they can get them from wherever they like. I don't know who takes them. It could be anybody."

There are 17,500 athletes in the village (they also have pool tables, for the ones who aren't having sex. If you're interested). And what's the magic number, for the London Games? 150,000 condoms. Unbranded. If anyone says the Games have been sponsored to hell, don't believe it.