Duncan McCallum: 'In skin-tight black Lycra, I'm like a nerdy superhero'

HOLY smoke! Despite my best intentions and efforts, all my promises that I was not going to lose the fitness I had last autumn – losing weight, avoiding cakes and exercising throughout the winter – the bathrooms scales beg to differ. I'm a solid 4kg overweight.

There are always plenty of excuses. The bouldering room is too cold in winter, the nearest climbing wall is a 45-minute drive away, the gym is too expensive for just a four-month membership and I can't get on to the ski slopes as much as I would like.

But the plain truth of it is that I just lack discipline – too much Vacqueyras and too many good meals and cakes. I sometimes feel that hidden just below the surface of this vaguely sporty body is a huge bloater stuffed with fast food, chocolate and ice-cream, just waiting to explode.

I'm lucky enough to live near big hills and within a population that understands cyclists. Locals give you a wide berth and understand the efforts you are putting in.

Apart from a brief period in the late-1980s, when climbers went through a phase of loud Lycra, I don't do body-hugging gear. For men, no matter how slim you may be, the VPL – the meat and two veg look – only works in certain New York clubs.

However, today, and for the next two months, I will make an exception. Despite the humiliation of walking about like a duck in stiff shoes, despite the inevitable butt pain, the stupid macho drivers who think it is funny to honk and cut you up, it's time to embrace the torture of the road bike.

Standing there in my skin-tight, all-black suit of cold-weather Lycra, I look to all the world like some tall, nerdy superhero with a small pot belly.

Having spent almost all my sporting life on natural terrain, road biking still feels a little alien, somehow too urban, too serious, too sporty. After all, it's an Olympic sport with teams and, God forbid, rules.

However, it's one of those activities that, since I discovered it a few years ago, keeps suckering me in.

The best bike-training advice I was ever given was cadence. Try to stick at between 80 and 110 revolutions per minute. This efficiently helps the heart pump the blood and means you are never grinding too hard or spinning so fast that you bounce up and down in the saddle.

One of my favourite rides is from Roy Bridge to Newtonmore, on the A86. The climb out of the town towards Moy Lodge is enough to keep you honest, but not too off-putting for an early-season ride. The descents along the lochside towards the car park at Creag Meagaidh are fast, open and fun. The lack of caravans wobbling past or slowing you down on the single track, is a blessing at this time of year.

After 20 minutes, I rediscover why I actually like road biking – travelling at speed under your own steam, the views, the smells – it all comes back.

Conveniently, just as I begin to feel peckish, along comes the WolfTrax MTB centre and a chance for me to replace some of the calories I've just burnt off. I take it. Carrot cake.

Hey, I deserve it – getting back on the road is cause for celebration. But now I'm hooked again, that endorphin drug pulling me out of the house and into the superhero suit. So beware, on a road somewhere is a thinning bald man with a fat man inside, just waiting to pop out and grab the nearest cake.

• This article was first published in The Scotland on Sunday, May 2, 2010