Swimming programmes are helpful for both the mentally and the physically handicapped as they weigh less in water, and this makes it easier for them to move their muscles, enabling them to improve muscle tone and co-ordination of movement. Pregnant women can swim during their pregnancy while many other sports are not suitable. Swimming is also useful in rehabilitation of injured athletes. Patients with rheumatoid arthritis can improve their aerobic capacity by swimming in warm water. Asthmatics should be encouraged to swim, as swimming is the sport that is least likely to precipitate an asthmatic attack, and the fitter they are the fewer attacks they have; swimming improves their breathing. Asthma is not a handicap in achieving excellence in sport as shown by the number of Olympic gold medal swimmers who were asthmatics.