I’ve signed up again at a local gym. This time, it’s just ten minutes walk from home so no more excuses about not going. Membership fees are reasonable and there’s a staggering number of classes on offer from ‘legs, bums and tums’ to ‘body combat’ whatever that is. Must try one of them someday. Now be impressed, I’m getting into the habit of waking up early, pulling on a tracksuit and shambling off up the road clutching a water bottle. How long will this last? Until the winter comes around again, I guess and it’s dark, cold and wet and ten minutes sounds like eternity. But there’s something I’ve always wondered. There must be about 50 machines, steppers, treadmills, cross trainers and stationary bikes. Thundering away from 06:30 to 21:00. Why haven’t clever people come up with a cunning wheeze to harvest the energy from all the gym bunnies looking oh-so-fetching in lycra? We seem to be able to generate power from sun, wind, waves and tides, surely connecting a running machine to a battery can’t be that tricky? Must ask my engineering friends at the University of Southampton or, wait, patent the idea, make a small fortune and build my very own gym in the shed.