I’ve never been one for gyms and I cannot abide traditional exercise. Until a couple of years ago, my preferred aerobic exercise was clubbing. Now that I'm getting too, ahem, mature to spend whole weekends with mascara streaked across my face and searching for a 4 a.m. taxi, I manage to keep the pounds off by walking everywhere. But my bum was still slinking southward.

Then I was presented with a pair of Earth trainers, which claim to increase the effect of exercise through negative heel technology. I didn't even know I had positive heel technology, but there you go.

NHT was developed by Anne Kalso, a Danish yoga instructor, during a visit to Brazil in 1957. Kalso noticed that the local population had a heel imprint deeper than the front of the foot. This reminded her of a yoga pose - achieved by flexing the foot and lowering the heel – and gave her the inspiration to connect yoga with walking in the form of a shoe.

The business that Kalso built fell out of fashion in the 1970s but was resurrected by an American shoe manufacturer in 2001, and the Earth brand was born. It’s main supplier is the website LoveThoseShoes.com, which offers a range of both trainers and sandals featuring NHT.

I have to say that they are not the most attractive of trainers to powerwalk in. It appears I have a pair of marshmallows on my feet. When I first started to walk in them I felt bouncy and looked - I was told - like a waddling duck.

So I waddled, to and from work every day and occasionally around South London during weekend power walks. My right cheek started to firm up, then my left cheek joined it (apparently this is normal). In all I lost 10 lbs over three months and my bum/thighs are less dimpled.

I wouldn’t wear them for running or aerobics as they are quite padded and can imagine they would make feet hot and sweaty. But now I wear them everyday and the results have lasted. Regular trainers, with their skinny soles and solid grounding bore me. Keep my heels low and my bum high, and I'm happy.

Earth sports trainers cost £115 on LoveThoseShoes.com,

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