Lucy Mangan: Burn, baby, burn

You probably can't tell from my typing, but I'm wearing Power Diet Shoes. These are boot trainers with 1.4kg weights in the soles, so you can burn 300 calories in 30 minutes rather than the customary 160 (ish. If there's one thing I have learned so far it's that numbers mean nothing unless you've factored in your height, weight, speed and favourite colour). Further benefits of the boots include "strengthened muscles in legs, hips, back and torso, improved posture (via pivotal weight distribution), better circulation and strengthened core muscles," according to the press release.

I certainly feel that my legs and hips are working that bit harder. In fact, the effect on the latter joints for the first few days have me begging for titanium replacements. But it'll take more than heavy shoes to have an impact on the gelatinous mass that exists where my core muscles ought to be. And whatever positive effects are being wrought on my sluggish circulation, they are undoubtedly undone every time I sit down, forget what I'm wearing and cross my legs, cutting off my blood supply from the left thigh down.

That I'm wearing the smallest size (three) also means the sole is almost as thick as it is long, making it impossible to flex my foot as I walk. Add to this the fact that the boot shape immobilises my ankles with the efficacy of prewar callipers and a very odd gait results that cannot be helping to improve-my-posture-via-pivotal-weight-distribution.

Still, it makes me very happy to think I am burning extra calories by walking around the shops. I consider filing a few patents detailing my plans for heavy gloves and leaded hats. But these commercial plans are displaced by a more philosophical musing. If carrying extra weight makes you fitter, why don't fat people become Olympic athletes? Or, if surplus poundage makes you burn more calories, how do we become fat? When I take the shoes off, my legs feel light as thistledown, but my mind still labours under these weighty questions.

www.powerdiet.co.uk

· Next week: Tim Dowling and dog do some Petsercise

Thanks to guardian.co.uk who have provided this article. View the original here.