High Intensity Interval Training, or HIIT (pronounced ‘hit’), can be done anywhere with little or no equipment, is simple to follow, and takes very little time. Great for beginners, as well as experienced exercisers looking for more challenge, a HIIT workout improves cardiovascular and muscular fitness, improves metabolism and increases fat loss. Good news for today’s time-crunched generation!
The HIIT workout challenges the cardiovascular system through quick, challenging bursts of activity, with exercisers working at 7 or 8 on a scale of 1 to 10, or at 70 to 80% of their maximum heart rate. Intense work is followed by a period of rest or lower intensity activity to let the body recover.
For example, the exerciser might perform a high knees run or burpees for 20 seconds, followed by 10 seconds of rest, repeating this cycle for four minutes. Total workout time would be 12 to 20 minutes and would include two to four rounds of different exercises in each four-minute block.
Another example would combine 30 seconds of high intensity and two to four minutes of low intensity exercise. Other popular HIIT formats include Boot Camp classes, Extreme Interval Training workouts, and the more recent SHRED workout.
HIIT is even being used for recovering heart patients. A recent conference hosted by the Ontario Society for Health and Fitness addressed the benefits of HIIT for older adults and cardiac patients. Erich Baumhard is a fitness counselor and personal trainer with the Town of Whitchurch Stouffville Leisure Centre, a ‘heartwise’ facility which works with Newmarket’s Southlake Hospital on the rehabilitation and treatment of cardiac patients. “Interval training is considered the best way for your cardio system to train and adapt,” says Erich. “HIIT can be introduced safely for cardiac patients to improve heart function and limit repeated cardiac episodes.”
Why has HIIT become the gold standard of fitness training? According to Shanon McMillan, personal trainer with York Region’s Coreshots Fitness, most of us have little time to work out and want a quick fix, and HITT training is efficient and great for calorie burning. “Thirty minutes of high intensity training is the equivalent of a one-hour run,” she says.
If this sounds too good to be true, consider the research. A study conducted by exercise physiologist, Dr. Peter Lemon, at The University of Western Ontario, found that six bouts of 30 seconds of high intensity interspersed with four minutes of low-intensity running burned over twice as much fat as typical aerobic cardio, despite spending half as much time on the treadmill.
So if you thought slow and steady always wins the race, especially when it comes to calorie burning, think again. In the past, exercise physiologists advocated ‘steady state’ cardio as most efficient for fat loss because relatively more fat (and less glycogen) is burned by the body as a source of fuel at lower intensities. As a result of this thinking, fat-burning workouts such as jogging, long walks and low intensity aerobics classes have dominated fitness programs for many years.
This research remains valid: your body does in fact burn more fat relative to glycogen when you jog, but you need to look at total fat burn. At higher intensities, you burn more total fat even if the fat/glycogen-burning ratio is lower; that’s because the number of total calories consumed is greater.
As an added bonus, a HIIT workout also burns more total fat due to the EPOC effect (excess post exercise oxygen consumption), resulting in an increase of as much as 37% more fat burning up to 14 hours post exercise. Comparatively, a long aerobic jog results in virtually no caloric burn post workout.
Most fitness trainers espouse blending both approaches to exercise. You need longer duration cardiovascular training to build your cardiovascular fitness base as well as HIIT training to build strength, burn fat and increase your metabolism. Research at The University of Western Ontario has shown that although short intervals and long runs produce similar fitness increases, they do so through different mechanisms. Interval work stimulates greater gains in muscle efficiency, while long distance running produces more adaptation in the heart.
“It’s important to mix it up,” Shanon advises. “Try doing two 20 to 30 minute HIIT workouts a week and one longer cardio workout of 40 to 50 minutes duration.” Ideally, include a yoga or stretching workout once a week as well, and if time permits, one weight-training workout a week to round out your program.
Beginners who want to be ‘bikini-ready’ in a month by benefitting from HIIT’s promise of quick fat-loss should be cautious of doing too much too soon. Too much HIIT can cause overtraining syndrome, injury and burnout. It’s crucial to consider volume and intensity when you are starting out.
Limiting HIIT workouts to two, maximum three, times a week with a 48-hour rest between sessions is important for recovery, as is sufficient sleep and healthy eating. “HIIT is fat-burning, but it can also cause injury,” says Erich. “People need to get away from just losing weight and focus on being athletically minded, building muscular strength and a good cardio base.” Balance and overall fitness are crucial to staying injury-free.
When beginning a HIIT program, be sure to include an adequate warm-up and cool-down, and be careful of progressing too quickly. “Beginners should do a minimum of four weeks of a periodized program of strength and cardiovascular training of four days a week to build a cardio base, and then introduce HIIT,” says Erich. He also recommends consulting a trainer before starting a fitness program and/or seeing a physiotherapist if you experience recurring injuries.
HIIT may sound intimidating and challenging, but if you progress gradually and build a fitness base, it can be an effective workout for every fitness level. “Everyone’s definition of intensity is different,” says Shanon, “and every workout can be modified to the individual. The problem is that people don’t take the options to modify.”
Shanon encourages her clients to know their limits, which makes them feel better about themselves and encourages them to return. “If people work too hard, they get injured and don’t come back. I always give three levels for an exercise and allow people to feel comfortable doing level one.”
For the more experienced, HIIT differs from what people have done previously. “Anything different benefits the body and challenges it,” says Shanon. HIIT can also be incorporated into just about any activity, for example, by using kettlebells, boxing, step, warrior ropes, spinning, rowing or running.
So, while HIIT can provide an efficient workout for every level, remember to progress slowly and know your limits. Find a trainer or instructor who can both motivate you and modify workouts to your fitness level. Look for a Boot Camp, SHRED, HIIT or Tabata class at your local fitness facility for a great way to build muscle and burn fat more efficiently.
This trend is here to stay, so jump on the bandwagon to greater health and fitness and try a HIIT workout today!
Tiffany Moffatt is a certified Personal Trainer Specialist, Fitness Instructor Specialist, Pre and Postnatal Specialist (Canfitpro certified) and freelance writer who has worked in the fitness industry for 25 years. tiffanysbeyourbest.blogspot.com.