As a badge slogan, 'I am officially fit for sex' may not be the most charming chat-up line. But an army of men wore it with pride yesterday.

The group, who included Sussex health chiefs, were badged up after striding along Brighton beach yesterday.

The challenge was to walk a mile in 20 minutes without ending up breathless.

The prize was a sticker proclaiming each successful man fit enough to have sex and everyone passed.

The air of triumphant machismo was increased by England's footballing exploits in the World Cup earlier in the day.

But the ultimate aim of the light-hearted challenge was more serious, concerned with where men are going wrong physically.

The walk, from Palace Pier to the Volks railway station near Brighton Marina, was part of the first National Men's Health Week.

Health professionals find men much more reluctant than women when it comes to looking after themselves.

Rob Davies, of the Men's Health Forum in Brighton, said: "Men generally won't go to doctors and don't know how to check themselves. Women are much more sensible about things like this."

Visitors yesterday were offered vital health information about diet, prostrate and testicular cancers, heart disease and sexual health.

The prospect of being labelled officially unfit for sex may have been a chilling prospect for those taking part.

But Stuart Welling, chief executive of Brighton and Sussex University Hospitals NHS Trust, confided the challenge was not meant to be particularly tough.

He said: "There's no doubt men are reluctant to go to their doctors when they have problems. We just wanted an innovative, fun way to get the message across."

Mr Welling suggested he and trust chairman Michael Whiting would wear their badges for a meeting that day with the NHS Modernisation Agency.

Among the health advisers welcoming the walkers was dietician Mhairi Donald, wearing a T-shirt saying 'I love MEN' - motivation, exercise and nutrition, that is.

Those who missed the walk can do their own test at home.

Kay Hyde, a clinical nurse specialist in cardiac rehabilitation, said: "As long as you can walk up 20 steps and feel comfortable at the top, you are okay for sex."

But John Elen, of the Morley Street Family Centre in Brighton, had a more imaginative - and potentially challenging - suggestion.

He said: "Perhaps people should have sex and then try to walk a mile in 20 minutes."