Scuba divers should workout with the iron and target the major muscle groups. Try squats, dead lifts, curls, situps, heel raises, leg curls, overhead and bench presses. Specialty excercises designed to improve your love life or your golf game are not necessary. Aerobics are optional if your weight training is fast paced. Most "hobby" excercisers work too slowly and don't push hard enough. Workout time, one hour, two-three times per week. Beginners and youngsters, not less than three/wk. The purpose is to facilitate handling of heavy gear, SCUBA, anchor rodes and the like, and to allow short bursts of extreme exertion while not pooping out or cramping.
Free divers should include some running or stairclimbing. The purpose is to expand chest capacity and wind. Serious spearfisherman must include sessions with the rowing machine.
Excercising regularly will improve your performance and possibly make you more resistant to DCS. There will be less lost time due to minor strains.
Divers should consider enhancing their diet with a broad spectrum multivitamin/mineral plus supplements of essential fatty acids. These would be omega 3 and omega 6, namely concentrates of flax, fish oil and wheatgerm oil. Women should include primrose oil.