Long-distance runners tend to be 'of a kind.'  Most look in need of a good meal.  Some are close to skeletal.  A friend of mine who is particularly jaundiced about track and field in general, and marathon running in particular, describes it as "stick-insect racing." 

So with that in mind ladies and gentlemen, would you welcome the new face (and indeed shape) of British distance running.  Weighing in at a majestic 20-stone plus, with a 21-inch neck, let's hear it for England's most-capped rugby player, Jason Leonard, who launches his new sporting career in the Bath half-marathon in 10 days' time. 

You may be surprised to learn that this will not be Leonard's first attempt at the distance. 

"The Grand Slam team did one somewhere in the Midlands in the early Nineties, but we stopped at lots of pubs on the way round, which really annoyed our fitness coach, Tom McNab," he explains. 

What time did he do it in?  "Can't remember.  I just know it wasn't closing time." 

But it's not only Leonard who is to be found putting the finishing touches to an intensive training regime in preparation for the big race. 

In a who's who from a golden era of English rugby, lining up alongside a human juggernaut three times the size of Paula Radcliffe will be, among other others, Rob Andrew, Mike Teague, Richard Hill, Peter Winterbottom, David Trick, Tony Swift, Jon Callard, Paul Ackford, Will Carling and a man who was so-often their nemesis, Australian fly-half Michael Lynagh. 

These galacticos have been assembled by another England great, and a man who was once voted the fourth hardest ever to play international rugby, Simon Halliday.  He may have been hard then, but he's not so hard now. 

"The lasts few miles are going to be almost unbearable," he whines. 

Now of course there's a charity involved.  CRY - Cardiac Risk in the Young - is an organisation close to many of the players' hearts, after a mutual friend, Howard English, died on the rugby field at the age of 32, and then amazingly his son, Sebastian, died 11 years later at the age of 15, from the same heart defect. 

The money that's being raised is to further genetic research into a condition that affects far more young people than you and I probably could ever imagine.  In countries such as Italy, you're not actually allowed to play sport until your heart has been checked.  In this country we are light years away from that. 

And so it's to help raise awareness that Leonard has been persuaded to buy a pair of tight-fitting Lycra shorts and pound the Georgian streets of Bath.  What's the furthest he's run so far? 

"Don't know.  But I was out for two hours.  So probably from my front door to the end of the garden." 

The course is twice round the city centre, and it's rumoured that Carling has set himself the target of lapping Leonard.  but the king of props is unfazed by such a challenge, or by reports that the Bath highways department are on standby to repair the potholes in the road caused by his size 11s digging giant holes in the Tarmac. 

"I tell you what's really pathetic," Leonard said. 

"Everyone else is moaning to each other by e-mail, saying their calf hurts and their thigh hurts and their legs hurt.  Ackford said he thought he was going to die during one of his runs.  But I think that what we could be about to witness is the modern-day re-enactment of the hare and the tortoise.  All the poncy backs will run out of puff with a mile to go, and I'll hang around at the back, and then overtake them all in the last 50 yards.  They'll never live it down.  Can you imagine their faces when they see me coming past them?"