By Fred Brenton BBC News website reporter

An aerodynamic Fred Brenton hopes his new look will do the trick

With less than a week to go, this whole marathon-thing has turned into something of a hair-raising experience.

I've had a close shave with some traffic while out training for Sunday's 26 miles, but nothing as near as when I sheared my mane the other morning.

In the quest for aerodynamics in the Cardiff Marathon on 3 October, out came the clippers and it was goodbye Donny Osmond mop and hello Kojak slap.

Actually, it was all over quicker than you could shove a lollipop in your gob and say "Who loves ya baby?"

At this point I need all the help I can get

Let's face it, you rarely see a long-distance athlete with anything approaching a mullet and you'll never spot stubble on a sprinter.

There must be something in this bald approach and what it does for their performance - it can't be just fashion?

After all, swimmers shave every available inch before they jump into a pool in the quest for speed, so it must be the same for runners, but without the water.

Fred's luxuriant head of hair failed to survive his training schedule

Maybe by taking on a more professional profile and losing a few inches off the top, I might be able to make up an extra few yards on my way around the course.

Thinking about it, I might even tape back my ears if it'll help me run that little bit quicker.

Who knows? But it's worth a try because at this point I need all the help I can get.

These are all the desperate efforts of a man seeking to calm his nerves after suddenly realising what he has let himself in for.

So far it's seemed very far away, but now the start and finish line are within sight it's feeling much, much too close at hand.

I was watching the so-called fun-runners in the Great North Run over the weekend but after realising I'd have to run twice as far, the word "fun" no longer seemed to apply.

By now I thought I'd be feeling as fit as fiddle but instead I feel more paralysed with fear and dread of not actually making it over the finishing line.

It might just be butterflies but after all this effort I don't think I could cope with not making it.

But if, worst comes to worst and I fail to make it to the Millennium Stadium, at least I'll leave behind a clean-shaven corpse.