High-Intensity Interval Training (HIIT): It’s for Everyone!

High-intensity interval training, or HIIT, sounds pretty intimidating. But HIIT workouts are FOR EVERYONE — and they’re especially good for those of us who are older or sporting a body type that isn’t exactly fit-tastic.

View HIIT as more of a broad concept than a rigid fitness activity that ratchets the intensity level off the charts, says exercise physiologist Katie Lawton, MEd. It’s a way to work out, not a specific regimen.

“What’s ‘high intensity’ is very relative,” Lawton explains. “You set the bar where it works for you.”

So, here’s how you can ease into HIIT to build a stronger, healthier body.

What is HIIT?

The game plan with HIIT is to mix repeated short bursts of higher-intensity aerobic exercise within a workout. (Notice that it’s “higher” and not “high.”)

“The focus is on varying the intensity level during the workout,” says Lawton. “That can mean going from low to medium intensity or from medium to high, then dropping back down before revving up again.”

But if you’re aiming for high intensity, that would be a level of exertion where you can only talk for a few words at a time. (Basically, expect to huff and puff.)

To get a bit more specific, high-intensity exercise typically means upping your heart rate to more than 70% of your maximum heart rate. The basic formula for calculating maximum heart rate is 220 minus your age. (Learn more about exercise heart rate zones.)

Other formulas exist, too, and may be beneficial to set a better target. Lawton suggests the Karvonen method, or heart rate reserve calculation, which also uses your resting heart rate to establish a max heart rate number.

How to do a HIIT workout

Think of it as a series of mini-challenges. Basically, you push harder for a short duration (20 seconds to a few minutes) before slowing down for an equal or slightly longer active recovery period.

Repeat this back-and-forth process throughout the workout. A beneficial HIIT session can last as little as 10 minutes, plus time for a warm-up and cool-down. Twenty to 30 minutes is typical. Rarely do HIIT workouts extend beyond an hour.

Aerobic exercises — the type of activity that can quickly elevate your heart rate — fit nicely into a HIIT session, says Lawton. Potential activities include:

• Running, either outdoors or on a treadmill
• Brisk walking wherever works best for you
• Cycling on a bike or a stationary bike
• Stair climbing on a stepper machine or in your house
• Rowing on a machine or waterway
• Calisthenics and body weight exercises such as lunges, jumping jacks, squat jumps and burpees

How often you do HIIT depends on the intensity level of your workout, but two to three days per week is a good target.

The benefits of HIIT

For starters, HIIT means being physically active — a sweaty status that far too few people reach on a regular basis. Research shows that only 28% of Americans meet weekly exercise guidelines.

Adults should aim to get 150 to 300 minutes a week of moderate-intensity aerobic activity, or 75 to 150 minutes of vigorous activity, according to recommendations from the U.S. Department of Health and Human Services.

HIIT can help you hit that goal and stay healthy. (Fast fact: Nearly half of the adult population in America has a preventable chronic disease — and 7 of the 10 most common chronic diseases can be “favorably influenced” by regular exercise. Pretty obvious connection, right?)

Benefits of HIIT include:

• Heart health: Researchers found that getting your ticker pumping a bit more vigorously on a regular basis can help reduce high blood pressure if you have obesity or are carrying a few extra pounds.
• Calorie burn: Shorter and more intense bursts of exercise can burn more calories than a slow-and-steady workout. An added perk? It takes less time, which is always a plus in a world with jam-packed schedules.
• Metabolism boost: Revving up your internal engine doing HIIT has a carryover effect, as your metabolism remains elevated for hours after exercise. That helps burn calories long after you finish working out.
• Fat loss: HIIT can help you lose body fat, especially if you have obesity.
• Reduce blood sugar: Study after study shows that HIIT can reduce blood sugar and improve insulin resistance, making it an ideal option for those with Type 2 diabetes or prediabetes.
• Better movement: A 2018 study found that a HIIT cycling program helped adults with knee osteoarthritis, with greater improvements in physical function than a continuous moderate-intensity cycling program.

Is HIIT safe?

As mentioned, HIIT can often help lessen symptoms of chronic diseases, such as heart disease and different types of arthritis, including rheumatoid arthritis and psoriatic arthritis.

Still, it’s best to talk to a doctor or a healthcare provider before starting a routine.

“They can help you set guidelines to exercise safely and successfully,” advises Lawton. “The goal should be to develop a program that you can do consistently in order to see the potential benefits.”

Tips to start HIIT

Lawton offers these half-dozen tips to enter the world of HIIT:

1. Ease into it. Start slow and look to ramp things up as you build strength and endurance, especially if you’re new to working out. Adjust the time and intensity to fit your level of fitness. “It’s the old idea of walking before you run,” encourages Lawton.
2. Always warm up. One of the main perks of HIIT is the limited amount of time it takes, but that doesn’t mean you should skip a warmup. Spend about 10 minutes stretching to get your muscles ready to make your workout more effective.
3. Find a buddy. Everything is better with a friend, and that includes HIIT. “People are often much more consistent with their exercise and successful if they do it with someone,” notes Lawton.
4. Use apps. Numerous apps and websites can help you build a program and even serve as a timer for your high-intensity bursts. Plus, it’s pretty nice when your first workout move is as simple as hitting “play.”
5. Track progress. Using an app or journal can help you chart progress. It can be pretty motivating to look at where you were versus where you are today and see the progress.
6. Don’t be afraid to push yourself. Effort brings results, and exercise tends to be more effective when it’s hard. The beauty of HIIT is that those “hard” moments can be limited to 20 seconds or so. “It’s a short time to feel uncomfortable,” reinforces Lawton.