Preventing running injuries does not have to be a stretch—but it should be. Stretching is one of the most important steps runners can take to prevent muscle strains and pulls and stay off the injured list as they prepare for a marathon.

"The one major drawback with increasing mileage for the marathon is increasing tightness of the leg muscles," said Dr. John Cianca, medical director of the Methodist Health Care Houston Marathon. "The more miles you accumulate, the shorter your muscles get. This can increase your risk of injury."

Regular stretching provides runners with two important components in their overall training program.

First, it allows the muscles to maintain their optimum length, which, in turn, makes them work more efficiently. Second, it allows the muscles to have more range of contraction.

"This is especially important for runners, because the more muscle you have to contract, the more muscle you have for shock absorption," said Cianca.

"This can determine whether your body will be able to withstand the pounding associated with long runs of eighteen to 22 miles."

The key to a good stretching program is consistency.

"Runners should try to make stretching as much a part of their routine as running itself," he said. "Stretching only once a week is not the best approach. Even if it is only five to ten minutes before or after a run, daily stretching can help prevent injuries."

Cianca says a complete stretching regimen should start with a brief warm-up, such as walking easily for a few minutes to loosen the muscles. Then, you should target stretching to the major muscles in the legs -- hamstrings, quadriceps and calves.