According to fitness coach Phil Wharton, a little stretching is much better than none. “It doesn't need to be a big ordeal,” says Wharton, who created the Wharton Performance program with his father, Jim. “If your time is limited, you can still take steps to prepare your muscles for activity.”

The Whartons teach Active Isolated Stretching, in which one group of muscles is contracted while its opposing group, in a relaxed state, is elongated. They also advocate dynamic stretching-holding exercises for just one or two seconds and then repeating them—as opposed to longer, static stretches. “Dynamic work is very similar to the running motion,” Phil Wharton says, “and it fires up the nervous system. It's all about blood flow.”

If you're like many busy people, you may neglect to warm up before running, which can lead to reflexive tightening of the muscles. “If you sit at a desk all day and then jump out in the evening to train," he explains, "you're shutting down, neurologically, the very muscles you need to use.”

To avoid this, Wharton recommends at least a short warm-up of dynamic stretches. “We usually suggest 8 to 10 repetitions for each exercise,” he advises, “very similar to weight training. And if something feels really contracted, you can repeat sets.”

Before your next run, try warming up for five minutes with these three dynamic exercises:

• Leg Swings: With one hand holding a chair or pole, stand on one leg and swing the opposite one, first forward 8 to 10 times, then backward the same number. Turn around and switch legs. “When you use your quadriceps, your hamstrings relax and elongate,” he says. “And vice versa.”
• Sideways Leg Swings: Begin in the starting position described above, but this time swing your leg to the outside and back for one set, then to the inside and back for a set. Turn around and switch legs. “Swinging out gets the abductor muscles, the outside hip, and swinging inside works the inner hip,” Wharton says.
• Shoulder Stretch: In a standing position, hold your arms straight out to your sides. First, bring them straigh out in front of you, then back behind your body, then forward again, gradually raising them higher with each rep until your hands are higher than your head. "Your knees should be slightly bent and abdominals engaged," Wharton says. “This is great for the shoulders and the upper chest because it opens up the thoracic spine."

A more comprehensive flexibility program, of course, produces the best results. “In a perfect world, we'd do a longer, active-isolated stretching session within about two hours of a workout or race, and then right before you head for the starting line, you'd do the swings,” Wharton says. “But if your schedule is limited, you can do a few movements when you wake up, especially the areas that are most contracted, and then do the swinging routine before you run. There really is no bad time to introduce flexibility. The important thing is: Don't do nothing.”