Squash racquets. A review of physiology and medicine.

Squash is a moderate to high intensity sport which demands specific fitness. Squash at any level places a high demand on the aerobic system for energy delivery during play and recovery. In addition, the sport requires bursts of intense, anaerobic physical activity involving the lactic anaerobic energy system. Players must possess appropriate levels of local muscular endurance, strength, power, flexibility and speed, combined with agility, balance and co-ordination. Irrespective of the standard of play, aerobic fitness training and specific anaerobic training should be undertaken by all who play or intend to play squash. Aerobic fitness for the individual who is new to the game and has little training background can be improved using low intensity continuous running. Training sessions and matches should be preceded by warm-up and flexibility exercises which may reduce the chance of injury and enhance readiness to perform. Despite squash being an indoor sport, it is likely that play in hot and humid weather may generate significant thermal loads with the associated elevations in heart rate. Fluid losses of 2 L/min and rectal temperatures of 39 degrees C may occur, thereby increasing the cardiovascular stress of participation and the risk of heat illness. Sudden death and other manifestations of heart disease can occur in squash, therefore advice regarding the safe participation for those with, or who have the potential to develop disease appears essential. For those under 40 years of age who are well and have no known heart disease, medical clearance is not mandatory prior to taking up squash; for such individuals, regular medical monitoring may be unnecessary. For healthy individuals older than 40 years of age irrespective of health status, but particularly for those with coronary disease or relevant risk factors, a medical checkup is recommended prior to, and at least annually after taking up squash. Healthy individuals older than 40 years of age with one or more risk factors require a medical checkup prior to commencing squash for the first time and at regular intervals (every 2 years) thereafter. These individuals should also have a medically supervised exercise test. Those individuals older than 40 years of age who have a known history of heart disease, most commonly coronary artery disease, may play squash if it is demonstrated that, on examination or following therapy or surgery, they can exercise safely to a high workload. Most eye injuries which occur in squash are related to eye/ball and eye/racquet contact. The incidence of injury is very low but such injuries may be totally preventable. Ideally, all players should wear protective eye apparatus. The "ideal' protective apparatus should comply with the Australian/New Zealand Standard for eye protectors for racquet sports. It should be recognised at the outset that there is a paucity of specific data regarding squash and pregnancy. Most women with normal pregnancies may continue to exercise and play squash particularly in the early stages of pregnancy but should notify their physician of their intention to do so. Musculo-skeletal injuries to the lower limb dominate most studies and common injuries include sprains and strains to the back and ankles. Of particular interest is the development of degenerative hip disease in elite squash players necessitating retirement or curtailment of activity in the third decade. Dealing with injuries and illness that are attributed to squash requires an approach based on prevention as well as on appropriate injury management.