HIIT can take your training and performance to the next level. Here’s everything you need to know about the popular exercise technique.
High-intensity interval training, or HIIT for short, was named one of the top fitness trends in the world for 2019, based on an annual survey by the American College of Sports Medicine.
This super hard, super effective style of training isn’t just the “it” workout of the moment—of the 13 years ACSM has been conducting this survey, HIIT also topped the list in 2014 and ranked in the top three for five consecutive years.
Why? Because it works, and it works fast. Whether you’re coming straight off the couch, training for a marathon, or even if you race for a living, HIIT training is good for your health and makes you fitter and faster.
What Are the Benefits of HIIT?
New studies on the benefits of HIIT make the news on a regular basis. Take, for example, this one from the November 2018 issue of American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. Researchers found that just two minutes of sprint interval training (in this case, four 30-second max-effort sprints followed by four and a half minutes of recovery for a total of 20 minutes) improved mitochondrial function—when your cells can change fuel to energy quickly, a benchmark for good health and exercise performance—just as well as 30 minutes of moderate exercise in a group of active men and women. In other words, busting out two minutes of really hard running can give you the same fitness benefits as slogging through 30 minutes at a steady, moderate pace.
What HIIT Means for You
Most of us already run a lot because as endurance athletes, that’s our thing. But even if you’re already fit, you can still reap measurable benefits from adding HIIT to your training regimen, says exercise physiology professor and coach Paul Laursen, Ph.D., endurance coach, author of The Science and Application of High-Intensity Interval Training (HIIT), and contributor to HIITscience.com.
For runners who like to go long, HIIT can be part of a smart base-building strategy. “Your base comes down to your mitochondrial capacity,” Laursen says. “Longer, lower-intensity exercise increases the number of mitochondria in your cells, which is why people perform long, steady endurance exercise to build base. But high-intensity training makes those mitochondria more powerful,” he says, noting that research also shows that high-intensity exercise performed regularly can stimulate the production of mitochondria, as well.
“Our research found that when well-trained cyclists performed two interval sessions a week for three to six weeks, their VO2 max, peak aerobic power output, and endurance performance improved by 2 to 4 percent,” he says.
Plus, recent research out of Australia suggests that doing your HIIT workouts in the evening won’t mess with your shuteye—and it could even curb your appetite after a session.
To help you get started, try any of these high-intensity interval run workouts.
On the Track
High-intensity track sessions move the muscles through the full range of motion, improving elasticity and enhancing coordination between your nervous system and muscles. With time, you’ll develop a more efficient stride at all your paces, says Joe McConkey, M.S., an exercise physiologist and coach at the Boston Running Center.
Begin with two 100-meter accelerations that include 40 meters at top speed, with 2 to 3 minutes of walking or jogging between. Build to 6 x 150 meters hard, including 80 meters at top speed, with 3 to 4 minutes jogging or walking rest. Over time, increase the number of repeats to 10, lengthen reps to 300 meters (running nearly the entire distance at top speed), or reduce the rest interval to 1 minute.
On the Trails
It adds to the challenge, but running fast over softer, less-groomed terrain like bridle paths, trails, or grass can increase agility and athleticism—or your ability to run with the “precise amount of power, speed, and coordination needed for efficient movement,” McConkey says.
Because of the terrain and potential strain on your leg muscles, ease into off-road workouts. Do five 30-second pickups at a moderate intensity during an easy 20-minute run, and build up to ten 60-second near-all-out bursts during a 40-minute run. From there, progress to running five cycles alternating 30 seconds of all-out running with 90 seconds jogging, then to 10 cycles alternating one minute easy with one minute super hard. Just be careful not to trip.
On the Hills
Inclines are a great venue for super fast speedwork. Compared with a flat surface, hills reduce the impact on your legs and limit your range of motion, thereby lowering the risk of strains and pulls. Plus, hill repeats build muscle power, which helps you run more efficiently on level ground, says McConkey.
On an incline, start with three 30-second moderate repeats and walk down the hill for recovery. When this becomes comfortable, progress to 4 x 1 minute near all-out efforts with a downhill jog and an additional 30 to 60 seconds jogging or walking rest. Over time, add additional reps, extend effort length up to two minutes, and aim for steeper hills, says McConkey.