It was only a matter of time before someone decided to do Zumba outdoors. As it turns out, that someone is instructor Ashley Green. Rock up to the big red bandstand at the centre of Clapham Common and bop to the latest, most infectious tunes. Classes make use of Wireless Fitness’s transmitting system, which beams songs directly to your headphones. Classes go ahead rain or shine. No booking required, but you must be 16 or over.