Stacey Berisavac has always been physically active, but the North Vancouver woman admits that for a time several years ago she became practically obsessed with exercise, working out for hours a day, running and winning marathons. She knew she had to make healthy changes once she became a mom seven years ago. She wanted an effective, balanced exercise program that wouldn’t devour her time. That’s when she discovered high-intensity interval training, better known as HIIT.
HIIT workouts alternate short bursts of intense exertion with brief recovery periods. Think sprinting for 50 seconds and then jogging, walking, or resting for 10. Aside from sprinting, the exercises could include movements such as lunges, pushups, planks, sit-ups, squat jumps, biceps curls, shoulder presses, and so on. The crux is to go all-out, recover, then repeat.
“HIIT workouts are usually full-body and incorporate functional and compound exercises, meaning they engage more than one body part at a time,” says Berisavac, a former personal trainer with a degree in health science and kinesiology, in a phone interview. “What makes HIIT so effective is that the harder you work, the more oxygen your muscles use and the more fat they’re using to fuel your workout.
“You need little to no equipment,” adds Berisavac, who does two to three HIIT workouts a week. “You can do them at home or in a gym or at a park. There’s so much flexibility and versatility.”
Although the format itself isn’t new, HIIT topped the American College of Sports Medicine’s recently released list of the top global fitness trends for 2014. CrossFit, Tabata, and P90X are all forms of high-intensity interval training.
Because they require such extreme effort, HIIT workouts are typically short, anywhere from about 12 to 40 minutes. That makes the format especially appealing to those who want to make fitness part of their routine but don’t have the time for hourlong runs or spin classes. But it’s the form’s effectiveness that’s driving its popularity.
According to the American Council on Exercise, this type of training increases anaerobic and aerobic fitness levels, leads to increased insulin sensitivity, and reduces abdominal and subcutaneous fat.
A study published in the Journal of Applied Physiology in 2006 found that seven HIIT sessions over a two-week period increased fat-burning capacity in women. Another study published that year found that after eight weeks of doing HIIT workouts, people could cycle twice as long as before while maintaining the same pace.
According to the IDEA Health and Fitness Association, oxygen consumption remains elevated after a HIIT session because the working muscles restore physiological and metabolic factors in the cells to pre-exercise levels. This means higher and longer calorie-burning well after the exercise has finished.
IDEA has also found that some cardiac-rehabilitation centres are starting to include interval training for heart-disease patients as a means to improve cardiovascular function. Although conventional low-intensity exercise yields similar gains, improvements from interval training happen with fewer sessions and in a shorter time.
“The great thing about HIIT is that it can hit all levels of fitness in a short amount of time,” says Serena D’Eath, lead trainer at BodyCo Fitness’s Deep Cove location (385–489 North Dollarton Highway). “Nowadays, people don’t have a lot of time. You can be in and out in 30 minutes. You’re doing core work through the whole thing. You get your heart rate up through the whole thing.”
D’Eath, who’s also a personal trainer, notes that the duration of the high-intensity sets and the recovery periods can vary; she might do those aforementioned 50-second bursts followed by 10-second recovery periods or perhaps switch it up to 30 seconds of full-throttle cardiovascular exercises followed by 15-second rests.
“Your body adapts to things, and that’s the beauty of HIIT: it’s always changing,” she says. “If you’re always doing the same training, you get the plateau.”
As with any form of exercise, however, there’s always a risk of injury. D’Eath suggests people get the okay from their health-care provider before starting high-intensity interval training, especially those with high blood pressure. Proper technique and breathing help reduce the chances of getting hurt.
Lacey Kondi, founder of Kondi Fitness (100–1462 West 8th Avenue), says she started to incorporate HIIT into her own workouts about a year ago.
“It has improved my overall body strength and coordination,” she says. “I love to start my morning with interval running because I feel fresher and more alert for the rest of the day.
“It maximizes results very quickly,” she adds. “People really challenge themselves. It’s a balance of cardio and strength, so you get all that your body needs. It’s addicting, too.”