Speed up, slow down, speed up, slow down. This may sound like a typical drive home in rush-hour traffic, but we’re actually referring to running intervals, a workout most runners love to hate.
Interval training can be extremely hard on the body, but, then again, that’s the point. In fact, a 2016 study showed that just one minute of high-intensity exercise can be as effective as 45 minutes of less intense endurance training, illustrating the amount of stress put on your body in a very small amount of time. But in order to take advantage of your hard work, it’s important to understand the importance of recovery and how to execute it properly.
Recovering Between Intervals
Interval workouts can call for just a few faster sessions, or on the higher end, 20 or more interval sets, with an equal number of recovery periods in between. Each burst of high intensity must be accompanied by a chance for the body to slow the heart rate and prepare for the next interval.
Chris McClung, a running coach and the co-owner of Rogue Running, recommends that athletes continue to move during recovery periods instead of coming to a dead stop. He adds that runners should be especially careful not to hunch over with your hands on your knees. This action can close off your lung capacity and make catching your breath much more difficult.
“You want to keep your muscles engaged and blood flow active,” he says. “Walking or very easy shuffle jogging will accomplish that, while you also keep your breathing and heart rate under control.”
Control is a key word here. While the length of each recovery session varies depending on the workout and your individual goal, you should aim to get to a point where you feel your breathing is fully controlled. This usually means maintaining a slower pace for 3–4 minutes before increasing your speed for another round.
However, in terms of finally bagging that elusive PR, McClung coaches his athletes to cut back on recovery time, shooting for the 45–90-second range. This will mimic the conditions you might face during a race, especially near the end when your oxygen intake is less efficient and your body is begging for more air.
On the other end of the time-frame spectrum, Ashley Thompson, a Road Runners Club of America -certified running coach from Austin, Texas, warns against the dangers of recovery sessions that are too long. Not only will these extended recovery periods keep you from executing a proper interval workout, you’ll also take longer to get back up to full speed. She cites research from Jack Daniels, PhD, that shows it takes about two minutes to reach the point where your system is working at its maximum.
“Because you’re trying to stay at a certain level of oxygen consumption, a short rest allows a runner to ramp back up to max levels sooner,” she says.
Recovering After an Interval Run
By nature, an interval run pushes your body to extremes by reaching (or nearly reaching) your VO2 max. This is extremely taxing on the body and should be kept in mind when making a training regimen or planning other activities. Both McClung and Thompson recommend one interval workout per week, noting that they should be part of a well-balanced training plan that includes longer, slower runs, cross-training and other types of speed work.
Each interval run should be followed immediately by a cooldown of 1–3 easy miles (depending on the runner’s goal) and post-run stretching. To kick-start your body’s recovery, make sure to consume a balanced meal of carbs, protein and fats within an hour of finishing the run.
McClung maintains that recovery is a truly personal process, and he stresses that each runner should test different approaches to find what works best for him or her.
“This formula might include stretching, strength exercises, foam rolling, massage, doing a short and easy recovery run, and, of course, plenty of sleep,” he says. “Just remember, recovery is not passive. Movement equals blood flow, which equals healing.”
What to Know Before You Go
Interval runs are an extremely effective way to increase raw speed, but they aren’t for everyone.
“Most recreational runners don’t need intervals,” Thompson says. “I don’t assign intervals until a runner has a consistent mileage of at least 30 miles (per week) for 3 months and is trying to get onto the podium.”
And they aren’t one-size-fits-all, either. McClung recommends working with a running coach or personal trainer who knows how to put together a plan to help you reach your personal goals.
“I commonly see runners cherry-picking interval workouts from running magazines, thinking that doing them randomly will make them faster,” he says. “And while that might be partially true, every speed session in a training block should work together to achieve optimal results.”
While interval running might not be for everyone — and it’s certainly no walk in the park — high-intensity exercise has some serious benefits as long as you execute it correctly. With the right balance of high-intensity workouts, endurance training and, of course, recovery, your fastest and best running is well within reach.