Although they are not common to everyone, sports injuries are something every athlete has to watch out for. While some are caused by something as simple as slipping and falling, a larger cause for injuries is often the lack of a proper warm up.

There are two reasons to warm up before exercising: to enhance one’s athletic performance and to prevent straining muscles. The reason for injury is the increasing blood flow as a result of warming up.

“Relaxed, sitting in your chair and reading this column produces a relatively low 15 to 20 percent of blood flow to your skeletal muscles,” former Olympic coach Gale Bernhardt said on an article of hers. “Most of the small blood vessels (capillaries) within those muscles are closed. After 10 to 12 minutes of total body exercise, blood flow to the skeletal muscles increases to some 70 to 75 percent and the capillaries open.”

In essence, this means that warming up safely and not to the point of exhaustion will allow the capillaries to open, making sure the muscles are prepared for more intensive exercise. It is important to warm up in a way that does not tire one out – this misses the whole point.

The amount of time spent on a warm-up should vary with the intensity and type of exercise, especially since there is no hard evidence on recommendations. Typically, recommendations range from 10 to 20 minutes for a warm-up. For highly intensive exercise, it is recommended to warm up for more than 20 minutes.

Then comes the question of what exactly a warm-up entails. Recent studies have shown that stretching or doing push-ups any way that is not similar to one’s actual workout or exercise is not recommended. Rather, people should base the warm up on the type of exercise they plan on doing. If they plan on running, for example, they should start by jogging slowly. For swimming, start by swimming slowly. Running, swimming or cycling are all exercises that are generally recommended. The exercise should get more intensive over the period of one’s warm-up.

“You can include short segments of gradually increasing intensity in the 30 to 60 second range, with long rest intervals as you get closer to the high-intensity segment of your workout,” Bernhardt wrote. “In order to perform at your best and minimize the risk of hurting yourself, take time for an adequate warm-up.”