Sir, As I pounded away on a treadmill at the Ferry Centre gym this morning I pondered on the furious pedalling and rowing, lifting and pulling, stretching and bending going on around me and thought, not for the first time, that surely there is a boffin somewhere in the recesses of the university's research labs capable of devising the technology for recycling (no pun intended) the renewable human energy sustained in similar sweaty settings throughout the world.

Kate Lack (Mrs), Oxford