The gym? Forget it. You can body build even without getting off that comfortable couch. Mental exercise can increase strength almost as much as regular and strenuous physical practice, British researchers announced recently. Dave Smith and his team from the Manchester Metropolitan University, uk, measured the push that 18 male volunteers could exert with their little fingers. Six of the group were asked to repeat the exercise twice a week for a month. Another six had to imagine doing the workouts, aches and all thrown in, but not actually do them. The rest were asked to do absolutely nothing at all. About a month later, when these volunteers were tested again, the Smith and his colleagues discovered that the average strength of the physical-practice group had gone up by 33 per cent, and that of the mental-practice group by 16 per cent. The group that had nothing to do stayed roughly the same. "It's due not to what's happening in the muscle but in the brain,' Smith explained. The researchers think that imagined exercises initiates the same motor programme in the brain as real exercise, and improves neural pathways ( New Scientist , Vol 158, No 2128).