By the time you read this, I will have entrusted to a close friend an envelope containing a cheque for £100, made payable to the United Kingdom Independence Party.

I feel like I probably owe you an explanation.

I'd been thinking about new year's resolutions and how fundamentally evil and depression-inducing they are: around half of us make them, depending on which survey you trust, but a tiny fraction actually keep them. Telling yourself you have to start doing something - or, even worse, refrain from doing something - for the whole of the rest of the year, or even for the rest of your life, has got to be just about the most perfectionistic, high-pressure demand you could make of yourself. We don't like being told we have to do things, even by ourselves, so subconsciously we rebel. And the nation's gym-owners are left cackling with manic glee at how much money they've amassed, and how little they'll have to do in return, since by February their gyms will be ghost towns again.

So if you haven't already abandoned your resolutions, I urge you to do so now, and do this instead: decide to do something for just 30 days - much less pressure that way - and then write a cheque to a cause you really dislike. Give it to a friend who likes you enough that if you don't stick to your plan, he or she will mail the cheque. This is why, if I don't go to the gym three times a week, starting today, for the next 30 days, this nation's vibrant community of swivel-eyed far-right eccentrics will be 100 traditional British pounds better off. (I couldn't quite stomach choosing the British National Party, though the logic of the idea surely demands it.) I've also signed up to the insanely clever website HassleMe.co.uk, which will remind you by email about anything you want, but does so - crucially - at unpredictable intervals so that your brain can't easily adapt to ignoring the prodding.

The cheque technique comes from the psychotherapist Albert Ellis, who notes that one of its effects is to put things vividly in perspective: going to the gym on a dark winter morning might seem awful, but is it really as awful as those people you detest getting that cash? You need to choose a sum of money that hurts, which might be much less or much more than £100. There's a possibly apocryphal story about a Las Vegas casino owner who put up billboards around the city promising £100,000 to anyone who caught him smoking.

There is, I realise, something rather aggressive, even militaristic, about this approach: in the long run, I'd rather want to go to the gym for positive reasons. In the meantime I'm just happy to know I'll actually be going, spurred on by the bright orange mental image of Robert Kilroy-Silk MEP. I know he's technically not in Ukip any more. But talk about a powerful motivator.

· oliver.burkeman@theguardian.com