Literally the complete book of walking--if Kuntzleman hasn't said it, it's not worth saying. Kuntzleman--editor of Rating the Diets (1978) and a gung-ho YMCA trainer--begins with a chatty, if lengthy, pitch on why those of us left behind by the joggers should walk: it's as effective as jogging, easier to stick to, more civilized, and doesn't require medical attention. Its manifold benefits include reduction of blood pressure, insomnia, and weight, as well as mitigation of arthritis and the ravaging effects of age. All this is documented in lively style and triplicate, with trainers, scientists, and resurrected converts testifying to the miracle of walking. For walking to be exercise, says Kuntzleman, the walker must maintain ""target heart rate""--that is, his maximum pulse rate minus 20 percent. He provides charts to compute this as well as different regimes graded according to physical condition. With specific goals (so many minutes per day), we should have little problem logging our time. He also provides a consumer report on track shoes (New Balance, yes; Adidas, okay; Earthshoes, no); walking itineraries--with maps--for 24 major U.S. cities; and an amusing roundup on world records in walking: backwards and forwards.