How Often Should You Run Interval Sprints While Running?

Jun 30, 2011 | By Kate Brennan

Speed work, or intervals, is an important aspect of training and can improve your running. Interval training will help you start your runs faster, finish strong, burn more calories and run a faster pace overall. You should incorporate enough speed work into your training to help you meet your running goals, but avoid incorporating too much, as this can lead to injury.

Types of Intervals

The terms speed work and intervals can be used to describe many exercises. Some classic examples are track repeats, hill repeats and fartleks. Track repeats are usually run on a track or grassy field. Running a 400-meter lap around a track five times is an example of a track workout. Hill repeats involve running up or down a hill for a set time or running the length of the whole hill, then recovering on your way back to the start. Fartleks are bursts of speed mixed in with running at a sustainable pace.

Recommended Amount of Speed Work

The type of speed work you do depends on your goals, but it is important to do it often and to mix it up so that your body does not get too comfortable with it. However, just as you can run too many miles and suffer from over-training, you can do too much speed work. American marathoner and Olympian Kara Goucher suggests that a good rule of thumb is to dedicate 25 percent of your weekly mileage to speed work or intervals of some sort.

Recovery

Ideally, you want to do enough speed work to improve your runs and help you achieve your goals without burning yourself out or getting hurt. Track repeats, fartleks and downhill repeats all stress your hamstrings and calves, while uphill repeats stress your quadriceps and calves. You should take at least one "easy" day in between workouts to give your body time to recover. An easy day can be a rest day, a cross-training day or a slower run.

Injury

Interval training places a lot of stress on your body and could turn a small injury into a big one. If you are injured or think you might be developing an injury, you should avoid intervals. Speed work can benefit you greatly, but an injury can set your training back weeks or even months. Add warm-up and cool-down periods with stretches to your workouts to help you perform better, prevent injury and recover more quickly.