When introducing speed work into a training program, sprinkle it in small doses into your routine. Running faster will force you to start using your previously hibernating fast-twitch muscle fibers, and doing too much too soon can result in injury.

Adding strides can be a gentle, effective way to speed up. To do this, find a flat stretch of road and accelerate for 15 to 20 seconds. When you are close to top speed, gradually decelerate back down to a jog. Repeat four to six times, taking a minute between repeats to catch your breath. Remember, these aren’t all-out sprints, but short accelerations. Focus on relaxing your form: get on your toes and lift your knees more than you normally would.

In the beginning, a set of four to six strides two to three times a week after your regular runs is plenty. As your training progresses, strides will become speed maintenance and a warm-up routine for more advanced speed workouts.

—Mario Fraioli is the senior producer at Competitor.com. He was a cross country All-American at Stonehill College, has run 2:28 in the marathon, and coaches the Prado Women's Racing team in San Diego.