Authored by Andrew Evans, ACE Health Coach at Hilton Head Health
You’ve probably heard of high-intensity interval training (HIIT) before, but do you know what it really means? HIIT is a training method involving alternating between periods of high-intensity intervals of exercise and periods of lower intensity intervals called active recovery. It is one of the most preferred ways of exercise because of the many benefits it provides. The benefits should convince you to make HIIT a part of your regular routine.
The Physical Activity Guidelines for Americans provides different options for us to choose how to meet activity recommendations for a healthy lifestyle. The recommendations are as follows:
|Aerobic Physical Activity||-150 minutes per week of moderate-intensity aerobic activity OR -75 minutes per week of vigorous aerobic activity OR – a combination of both, preferably spread throughout the week.|
|Muscle Strengthening||– moderate- to high-intensity muscle-strengthening, (body weight, bands, or dumbbell resistance) at least 2 days per week.|
|Move more, Sit less||-short bouts of light-intensity activities added up throughout the day -ex: 5-10 minutes of activity, 4-5 times a day|
One option is completing 30 minutes of moderate-intensity 5 days a week or 25 minutes of vigorous-intensity 3 days a week. If this is unattainable, even multiple short bouts of light-intensity throughout the day can offset some of the risks of being sedentary.
The most commonly used excuse for not exercising is due to lack of time. Time has become our most precious resource in a world where everything demands it. So how can we find a way to get the health benefits of exercise without sacrificing so much time each day? The answer is HIIT. These types of workouts are designed to be short in duration due to the high intensity. It’s all about getting the most bang for your buck, and HIIT delivers that option. HIIT workouts can provide the many health benefits that a longer duration steady-state workout can but in much less time.
Arguably the biggest benefit of HIIT training is that it can actually save you time. It’s all about how to get the most bang for your buck. Shorter HIIT workouts can provide the many health benefits that a longer duration steady-state workout can but in much less time.
For those of you like me that find it hard enough to exercise each day, this may provide an opportunity to be more consistent in your fitness routine.
Not only is HIIT a great option when you’re in a time crunch, it also has the benefit of burning similar amounts of calories as endurance exercise in a fraction of the time. There is a concept known to the fitness community called Excess Post-Exercise Oxygen Consumption (EPOC) or sometimes called “after-burn”. This is due to your metabolism staying elevated after you finish a HIIT workout. To better understand what EPOC is and its effect on our body is to think of a metabolic “campfire”.
Low-moderate intensity endurance exercise, like walking on a treadmill or using an elliptical at a steady pace, will provide a spark and slow gradual burn. When you finish the workout your metabolic fire dies down quickly, like throwing water on your fire.
HIIT on the other hand provides a much larger spark. Every bout of high intensity is like throwing lighter fluid on your metabolic fire. And after you complete HIIT, the flame dies down gradually over a longer period of time. The body burns 5 calories for every liter of oxygen consumed and oxygen consumption remains elevated while your body returns to its pre-exercise levels. The EPOC effect from HIIT can add 6%-15% total energy cost to the exercise session.
As well as HIIT providing the benefit of burning more calories through EPOC, it’s also better at maintaining your muscle mass than low-moderate endurance training. Since your muscle mass determines your metabolism rate at rest, the more muscle you have, the more calories you burn.
In addition to HIIT contributing to high-calorie burn and weight loss, studies show that HIIT may be more effective at reducing certain health risk factors and improving overall cardiovascular function than compared to continuous moderate-intensity exercise.
Research indicates that HIIT improves aerobic capacity 5-7% more than continuous moderate-intensity exercise. Aerobic capacity (or VO2max) is the measure of the ability of the heart and lungs to get oxygen to the muscles. This is determined by the capacity of the heart to deliver more blood with each beat.
Research also shows that HIIT is more effective than continuous moderate exercise in decreasing risk factors of metabolic syndrome including improved fasting blood sugar levels, improved insulin sensitivity, and increased HDL cholesterol (the good cholesterol). Due to a large reduction in cardiovascular risk factors, epidemiologic reviews suggest that getting fit may be more important than losing weight. This is because there is a stronger link of aerobic capacity to cardiovascular mortality than obesity to mortality. Therefore it is suggested that it may be more beneficial to target aerobic capacity before weight loss, although improvements in both would be ideal. The great news is that HIIT is a way we can include both.
So why is this important? By engaging in HIIT you can improve your capacity for tolerating higher intensity exercise and performance in everyday life. Daily tasks that require more effort may become easier than previously before. You may find that climbing a staircase is less difficult and you’re less out of breath. Carrying heavy bags of groceries from the car into the house may get easier. Doing yard work or shoveling snow may not be so exhausting.
Now I know right away that some of you are saying, “wait, fun and exercise don’t belong in the same sentence together,” and in some ways, I could agree. But many times the workouts that we find more difficult physically are more stimulating intellectually. By introducing intervals of varying intensities we are required to constantly be engaged in the workout. For many, the intervals provide motivation throughout the workout, often pushing you to get the most out of the exercise. Even though you may work at a higher intensity, it is for a short duration with the promise of a rest or recovery interval. (You may be sucking wind but you definitely won’t be bored.)
Another benefit of HIIT is that it doesn’t require any equipment. All that is required is ample space to move your body in. This makes it great because your body becomes your gym, and you can do a HIIT exercise wherever you go. If you’re traveling for work or vacation you can get a HIIT workout in your hotel room, at the park or at the beach. For individuals with balance or mobility issues having a stable surface like a counter may provide additional support.
One of the most popular HIIT methods we use at Hilton Head Health is called Tabata. Tabata style training is 8 rounds of a given exercise, with one round being 20 seconds of “work” followed by 10 seconds of rest. Using this method, each exercise you choose should take 4 minutes. So if you decide to do 3 full-body exercises, you can get a beneficial workout in as little as 20 minutes including a warmup and cool down. The wonderful thing is that you can adjust the number of rounds to shorten your workout if you’re strapped for time, or if you’re looking to do a larger variety of exercises.
While HIIT does provide many benefits it is suggested for most to use in combination with other training methods. If this is a new training method for you, begin by adding only one day a week and slowly increase as tolerated. Due to the nature of high-intensity exercise it is suggested that HIIT be done on alternating days. It may not be suited for individuals who are at a high risk of injury or have serious medical complications. For these individuals, seeking clearance from your primary care physician or cardiovascular specialist is suggested before beginning HIIT.
Below is an example of a HIIT treadmill workout you can try or modify.
ACE Health Coach