Running, for some, is about letting the rhythm of the pace take over so that mileage doubles as meditation. But if you’re training for a race, it can be beneficial to add intervals—short periods of increased effort at much higher speeds punctuated by slow jogs to recover—into your weekly schedule.
“Interval training is extremely important for improving running ability,” explains Elizabeth “Corky” Corkum, a top instructor at Mile High Run Club in New York City, private run coach, and runner who has crossed finish lines countless times, from 5Ks to ultra-marathons. “It depends on the person and their goals, but if the goal is to become a faster runner, intervals are a necessary component.”
Why are intervals so important for runners?
More and more research has found that interval training can be beneficial when it comes to exercise in general, in terms of calorie-burning, muscle-building, and more—especially since it produces benefits from very short periods of time, a bonus for busy types who are looking for the biggest bang for their (sweaty) buck.
For runners specifically, the benefits go way beyond more intense cardio. Everyone has a combination of slow- and fast-twitch muscle fibers, Corkum explains. Running long distances at a moderate pace will train the slow-twitch, increasing endurance, while running intervals will activate the fast-twitch. That activation can help improve speed and power, which is especially beneficial if you’re a runner who likes to run a variety of distances.
“Some runners run every race at the same pace,” she says, from a 5K to a marathon. If you work on training both your slow- and fast-twitch muscles, you’ll be more likely to zoom through shorter races while still maintaining steady endurance for longer treks.
“You have to get comfortable being uncomfortable…that’s the sweet spot where a lot of progress happens.”
Corkum says the discomfort involved in interval training can also teach you to push yourself harder, which may help you power through pain, toward the finish line, on race day. “You have to get comfortable being uncomfortable,” she says. “A lot of us don’t want to do it, but that’s the sweet spot where a lot of progress happens.”
How to start running intervals
Corkum recommends incorporating intervals into your training plan once or twice a week, on non-consecutive days. “I would never do more than twice per week, simply because the stress on the body that comes from interval training is high,” she cautions. “You stress it to improve, but injury risk is going to go up.”
And you can keep it super simple. Generally, you want to alternate running at an all-out, intense effort with periods of recovery. So, you could do one-minute sprints interspersed with one or two minutes of recovery, or incorporate a ladder structure where you sprint and recover for one minute each, two minutes each, all the way up to five minutes, and then move back down that ladder.
Even less structured, you can use environmental cues to signal when to work hard and when to recover. Outside, it could be trees, mailboxes, or a certain number of blocks. On the treadmill, you could run hard until the end of a song or until the next commercial. “It always has to come back to some element of fun,” Corkum says. Otherwise, you won’t keep lacing up for the next run.