What's the best way to train for a marathon? Go on holiday

It's lonely being a long-distance runner. John Mullin decided to marry his fitness regime with a family break in Tenerife

Preparation – any top athlete will tell you – is key, and I'm no exception. The London Marathon may be a long way (26 miles and 385 yards, at the last count) but, hey, as long as you stick to your routine – the long Sunday runs, the short sprints, the fartleks, no schoolboy sniggering, please – there's no reason why anyone should have anything to fear. Even a fat, grey-haired crock with crumbling knees and a Gazza-type refuelling problem.

Plus, of course, it's important not to overtrain. Some people less experienced than I would make that mistake, but decades of practice have enabled me to know exactly when to slack off. Mental focus is, you know, almost as important as putting the miles in. As is carbo-loading ahead of the big day.

I have decided to vary my training regime this time out. Someone – the travel editor, since you ask – has mentioned to me that no less a world champion than Frank Bruno would decamp to Tenerife to hone bouncing off the canvas ahead of his major contests. I have no idea, and, indeed, no real interest in whether this is true, but it sounds to me a rather splendid idea.

Now, don't get me wrong, easyJet's great, but, leaving aside the ecological dimension, it's miles better for a short hop than it is for a four-hour, DVT-inducing ride. And wouldn't it be great if, instead of checking luggage into the hold, you could check in your three-year-old? Sixteen quid of anyone's money well spent.

Still, even an athlete as focused as I am will succumb to the holiday spirit after picking up the hire car and driving the 20-odd minutes to the Hotel Jardin Tropical on the south Adeje coast, a fine hotel built in what articles like these would suggest is the Moorish tradition.

In any case, it's better than the other functional concrete monstrosities, and boasts a stunning vista of La Gomera, a spa where the missus can disappear for hours on end, and two great pools the kids adore. And, for the dedicated runner, there's a fantastic bar to watch the sun setting.

Enough of all this, for it is now Monday, and just six days to go to the London Marathon. Truth is, I haven't run properly for six weeks because of various injuries, and I need to go out and see what my stamina is like.

It's lovely at 8am, and there are scores of like-minded folk pounding the path that leads for miles along the shoreline. No one would claim Tenerife is the height of sophistication, but, past the carbuncle shopping centre, there are plenty of lovely little beaches; the flowers are in bloom, and it is about to be a scorcher. Even the running is easy as I make sure to skip around the building site that brings my outward leg of the journey to an end after an hour or so. (Golf apartments, since you ask.)

And then it happens. Inexplicably, and having negotiated all obvious hazards, I crash down on my ankle – and it is agony. You know the way you want to cry, but it would be a bit unseemly for a 45-year-old burly Glaswegian? Particularly given four workmen are stifling giggles.

I get up and continue: how, I do not know, and I limp back to base. There is, though, a silver lining. There's no point in worrying about running any more before the big day: much more important to focus mentally. And to carbo-load.

This, dear reader, proves no challenge to an athlete of my standing. You could eat enough for a family of five each morning at breakfast – and each of this family of five does – and there are four excellent restaurants to choose from in the hotel. We also try La Vieja in nearby La Caleta one night without the kids, and it is fantastic. I am afraid, though, my assiduous carbo-loading – in this instance, of the local wine – is so impressive as to render detailed recollection an impossibility.

The kids? There are two excellent attractions – Loro Park, an hour's drive on the greener north of the island, and Aqualand, virtually next door. Loro Park is a parrot park, but they also have whale, dolphin and sealion shows there, and, though I am trying to keep my focus on the race, even I find them impressive. And my daughters, five and three, are wild about them.

Aqualand is brilliant. Twisting hoops of waterslides. The boy disappears for hours on end, returning with a back the colour of his Manchester United top. The bonus? Exhausted children and a decent night's kip for all.

And so it all comes to a close much too quickly: a night flight back, a morning to register for the marathon, and then the race the day after. My time? Well, it doesn't matter. But perhaps I didn't get the training/carbo-loading balance quite right this time.

How to get there

John Mullin and family travelled to the Hotel Jardin Tropical with Kids in the Med (0845 277 3300; kidsinthemed.com), which offers seven nights' b&b from a total of £3,099 for two adults and two children sharing a family room, including return flights from London and transfers. The hotel is currently running a "family summer added-value offer" including one free round of golf at a nearby course; one free entrance to the hotel spa with unlimited use of Jacuzzi, sauna, Turkish bath and therapeutic showers; one free evening meal for all children when dining with parents in selected restaurants at the hotel. Offer applies to holidays taken before 30 September 2008, excluding 1 to 31 August. Auto Europe (0800 358 1229; autoeurope.co.uk) offers car hire from £89 per week.