The big three

Unlike male athletes, the drawbacks for women include amenorrhoea, bone density loss and prolonged calorie deficit.

For women, the benefits of an active lifestyle are profound and well-known. There's a downside to everything, though. The injuries and physical risks that beset female athletes are less publicised. Millions of girls participate in high school sports and millions of women run worldwide. Like male athletes, they risk overdoing it by getting competitive. But unlike male athletes, the drawbacks include amenorrhoea, bone density loss and prolonged calorie deficit. These three associated symptoms are often called the female athlete triad. There is a recognised risk of cardiovascular disease as well, since women with the above issues can develop a dysfunction in their blood vessel cells.

The female athlete triad - symptoms of which include disordered eating, osteoporosis and decreased vascular dilation - generally occur when an athlete is too lean. The body starts to go into a starvation, all-systems-threatened mode. There are several important tips for combating the triad. First, an awareness of the symptoms helps women to avoid them. Eating a meal before exercise, hydrating two hours before activity and a meal again within 30 minutes of exercise are important. Weight-bearing exercises also benefit long-term bone mineral density. Finally, a daily dose of 1,500 mg of calcium and 400 mg of vitamin D are suggested for female athletes ages 11 to 24.

Among women who run at least six times a week, the prevalence of athletic-associated amenorrhoea is estimated at more than 40 per cent. According to a study led by the sports medicine researcher Anne Hoch at the Medical College of Wisconsin in Milwaukee, about one-third of ballet dancers (who, pound for pound, are fitter than international swimmers) suffer from disorders associated with low bone density.

The female athlete triad might sound imposing, but it's nothing compared to cheerleading. According to the National Center for Catastrophic Sports Injury Research in the US, cheerleading is the top cause of major injury in young women. Data from the Consumer Product Safety Commission shows that rates of injuries from cheerleading accidents have gone from nearly 5,000 in 1980 to close to 27,000 in the past few years. This accounts for roughly 65 per cent of all female catastrophic injuries in high school and college in the US.

Generally, athletes only have to worry about muscle strains, ligament injuries and tendon pulls. But if you're an acrobatic cheerleader, you also have to think about head and spine trauma, concussions and severe fractures. Watch out while tossing people in the air, jumping off pyramids and trying risky stunts. And definitely don't get too lean; you'll need all the oxygen you can get through your arteries.