Four days a week for the past 10 years — before the novel coronavirus caused most gyms to close their doors — I spent my lunch hour in a CrossFit class. Most CrossFit workouts mix weightlifting with high intensity interval training (HIIT), and they are usually short but intense, with intervals that spike the heart rate and leave you gasping for air. Motivated by a deep competitive streak, loud music and a coach shouting encouragement, I worked out harder than I thought possible, pushing my body to the limit. I left the gym each day drenched in sweat and flooded with endorphins.
I still exercise at noon but now train solo in the garage, my coach replaced by our family’s Boston terrier, who is more interested in napping than motivation. Five months into this routine, though, I’m struggling to achieve the high-intensity part of my HIIT workouts. I’m working out the same number of days but feel less fit, less motivated and definitely not excited to do it again the next day.
HIIT workouts are efficient and effective, and it’s possible to get an intense workout at home with no equipment. But to get results you have to push yourself to achieve the right intensity without putting too much stress on your body. To succeed at the HIIT game, you have to know the rules.
Here’s a look at what you need to know about HIIT, how to design your own workout and what to do to keep yourself motivated outside the gym.
Why HIIT workouts are so effective
It seems too good to be true, but studies show 30 minutes of interval training, which includes 10 to 20 minutes of warm-up and cool-down, has the same cardiovascular benefits of 150 minutes of moderate aerobic activity.
The benefits of HIIT training go beyond heart health.
“You’ll burn more calories from the workout itself but also the recovery period just after the workout,” says Evan Jay, a physician assistant and certified athletic trainer with Redefine Healthcare.
HIIT workouts are especially beneficial as we age. “It’s well documented that HIIT wins the race when compared to low to moderate exercise” in reducing fat deposits, including belly fat, says Debra Atkinson, founder of Flipping Fifty, which offers hormone-balancing exercise for women in menopause. “Not only is [belly fat] the number one complaint of women in midlife, it’s also a health risk.”
As with any workout, consult with your primary care doctor or cardiologist before starting something new. “You want to make sure your heart can handle it,” Jay said.
Creating a HIIT workout that fits your fitness
HIIT workouts are efficient, but to enjoy their calorie-burning, heart-healthy benefits you’re going to have to push yourself. HIIT is all about spiking the heart rate and feeling sweaty, out of breath and uncomfortable.
The good news is the workout will be over before you know it. All high-intensity workouts, no matter your fitness level, should last no longer than 30 minutes, including warm up and cool down.
Anything longer than that, says Erin Beck, a fitness coach and owner of eTONE Fitness, and you’re sacrificing intensity and power for duration. Pushing the duration too long means you aren’t hitting the sweet spot of intensity.
A common mistake with HIIT workouts is doing them every day of the week. Your body needs days off to recover, repair and build muscle. “For advanced athletes, I’d say four to five days a week,” says Alesha Courtney, a trainer and owner of Alesha Courtney Fitness. For beginners, Courtney recommends two to three days of HIIT workouts a week. “I think a lot of people forget the recovery time and that’s crucial,” she says.
The length and frequency of HIIT workouts — 30 minutes, three to five times a week — is fairly standard, but the ideal work-to-rest ratio within each session depends on your fitness level.
Beginners and those new to high intensity training should start with a 1:2 ratio of high intensity to rest. This means you push the intensity for 30 seconds, then rest for a minute. Intermediate athletes can work at a 1:1 ratio, either a minute on and a minute off or 30 seconds on and 30 seconds off, depending on the exercise. Advanced athletes can hit a 2:1 work to rest ratio, 30 seconds on and 15 seconds off.
If you’re not sure where you fall in the beginner-to-advanced spectrum, Beck recommends simply listening to your body.
“Those work intervals should feel really tough by the end of it,” she says. “At the first part of the interval you should feel like, ‘Okay I can do these jump squats’ and by the end of it you should feel like ‘No I cannot do any more, I’m toast, I need a recovery.’ Then you take a recovery.”
How do you know if you’re pushing hard enough during these intervals? One way is by checking your heart rate during the rest periods.
First, determine your maximum heart rate by subtracting your age from 220. If you’re 40, your maximum is 180. You want to hit 80 to 95 percent of this number in your work interval, so during your rest interval take your pulse and count the beats for six seconds. Multiply that number by ten and you’ll have your heart rate. A 40-year-old needs to keep her heart rate at about 16 or 17 beats per six seconds, for a heart rate of 160 or 170.
If, like me, you prefer to spend your rest time hunched over and panting, you can use a heart rate monitor or just go by your feeling of breathlessness.
Atkinson says she prefers breathlessness as a measure of intensity.
If you’re gasping for breath at the end of the interval, you’re doing it right. “Your body never lies. Your heart rate sometimes will,” Atkinson said.
Contrary to what coaches may have told you over the years, standing tall with your hands behind your head may not be the best position for recovery. A 2019 study found resting with your hands on your knees can help you recover much faster during interval training.
You don’t need equipment or even much space to hit your target zone. Exercises that use your entire body, like shadow boxing or kickboxing, are excellent low-impact ideas for a HIIT workout. Other great low impact options are lunges and squats, and you can add a punch at the top of your squat for a full-body move.
How to motivate on your own
As I’ve discovered during my months of solitary sweating, the hardest part of solo HIIT workouts is finding the motivation to push yourself without a coach telling you to keep moving.
Atkinson has two tricks to keep her motivated. The first is using an interval timer app. The clock ticking down “creates a sense of urgency. So if you can attach that thought process, ‘I’m blowing it if I don’t get to breathless before this is done,’ that can help,” Atkinson said.
Her second trick is putting on fast music — between 160 and 180 beats per minute. “Your body will naturally try to go faster to the beat during a faster song,” she said. (Spotify has playlists organized by BPM in the Running section.)
Courtney recommends finding an accountability partner or friend to keep you on track. She says many fitness trackers can sync with another person’s tracker, which means no more pretending you worked out in your garage when you really stayed in bed repeatedly hitting the snooze button.
“Music is a big thing,” Courtney says. “I know for me music is a huge motivator and I’m excited to work out if I have a good playlist.”
For Beck, the best way to stay motivated is by tracking and measuring your progress. She recommends what she calls “marking your start,” which means writing down what you accomplished on day one of your workout program.
“Train for a week, then check back on those numbers and see how much you’ve improved,” she says. “The only way we’ll be able to see if we’re getting stronger is if we know where we started. Then we can see how far we’ve come.”