Running helps prevent obesity, diabetes, hypertension, high cholesterol and heart disease. It also helps with mental health while burning between 450 and 1,400 calories an hour, depending on a runner’s speed and size. No wonder nearly 12 million Americans do it regularly and more than 37 million lace up their running shoes at least once a year. “You don’t need anything other than a good pair of shoes and somewhere safe to run,” says Dr. Margot Putukian, director of athletic medicine at Princeton University. Here’s how to optimize your run:

Don’t overdo it. Runners of all levels fall victim to the too’s—“too much, too soon, too hard,” says Dr. William Roberts, medical director for the Twin Cities Marathon in Minnesota. Start slowly, running half a mile, then walking half a mile—or walking a block, then running a block. People who do too much too quickly can develop problems like tendonitis in their heels or knees. For the average runner, a half hour five times a week is enough.

Don’t postpone a doctor visit. “People are notorious for trying to run through their pain,” says Dr. Tyler Cooper, a physician at the Cooper Clinic in Dallas and coauthor (with his father, Dr. Kenneth Cooper) of “Start Strong, Finish Strong.” “Be proactive. Go to the doctor before it gets bad. A lot of times just put-ting some orthotics [special inserts] in your shoe can change everything.”

Wear good, supportive running or cross-training shoes. Old or ill-fitting ones can lead to problems with your feet, ankles and knees. Replace shoes every 500 miles or so. For a 10-mile-a-week runner, that’s once a year.

Try softer surfaces. “Concrete is the hardest thing on your knees,” says Cooper, who prefers dirt roads or tracks because they “take some of the tension off of the joints. When you hit the concrete, it doesn’t give.” Grass is good, too, though watch for holes.

Be safe. Don’t put your iPod on too loud. It’s important to be able to hear cars—or someone calling to you for help or to warn you of danger. For early-morning or twilight runs, wear a reflective vest so you’re visible.

Hydrate. “Replace sweat losses and no more,” says Roberts. “Water alone is fine for most athletes.” Sports drinks, he says, “make little if any difference for a recreational or beginning runner, and if competitive running, only if nearing an hour.” Save the drink money for those new running shoes.