From Andy Bebington, London, UK
You outline research showing how varying stride length while walking helps burn more calories. However, it does more than that. It enhances muscle tone and overall fitness. This is the idea behind fartlek, a training method for runners. Practitioners vary their pace (and thus their stride length) while running through woodland or open country, switching from a gentle jog to a race-pace run to an all-out sprint and repeat (22 June, p 8).
Adherents develop muscles better suited for distance racing. You burn more calories and also enhance your racing potential.
