Freddie Flintoff and Usain Bolt join SFFC (the sporting flip-flop club)

Usain Bolt pictured at Old Trafford (GETTY IMAGES)

Flintoff's in the blue corner and Bolt's storming up the right wing, or at least they will be, in sporting job-swaps that should bring unseen speed to football – and a new level of laddishness to boxing.

Andrew "Freddie" Flintoff, the former England cricket captain noted as much for his off- as on-pitch endeavours, will step into the ring for Sky1 series 'The Gloves Are Off'. Coached by Barry McGuigan, the all-rounder-turned-heavyweight will take on a "credible" opponent on live TV.

And the fastest man on the planet? According to Sir Alex Ferguson, Bolt could turn out for Manchester United in a charity match next year. The sprinter is a fan and had already suggested his speed could be an asset.

Neither enterprise sounds like more than a stunt, but others have made more serious switches. Most recently, Alex Zanardi won gold in a Paralympic hand-cycling time trial more than 10 years after losing his legs in a motor racing crash.

Hayden Smith swapped funny-shaped balls when the Australian signed this year to American football side the New York Jets, after playing rugby for Saracens, the English team.

More than 70 athletes have won medals in different Olympic sports. In Beijing in 2008, Rebecca Romero added a track-cycling gold medal to the silver she won for TeamGB as a rower four years earlier in Athens.

But be warned, Freddie and Usain, if you're big in one sport, there's no guarantee you'll make it in the next. Michael Jordan, the best-ever basketball player, took up baseball in 1993 but swiftly returned after performing poorly for Minor League team, the Birmingham Barons.