What is High Intensity Exercise?

Work Harder, Burn More Calories

men doing box jumps in crossfit gym
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High intensity workouts are the latest trend in fitness. But what does that actually mean? Working to the point of complete muscle fatigue or until you throw up? Or something a little less intense, but hard enough that you can't talk.

One of the most important elements is the intensity of your workout, so it is important to get it right. While most guidelines recommend moderate intensity exercise most days of the week, working at a high intensity can help you burn more calories, save time with shorter workouts, and increase your fitness level.

Ways to Meaure Intensity

So, how do you know if you're working at a high or vigorous intensity level? There's no precise definition, but there are ways to monitor how hard you're working:

    How Often to Do High Intensity Exercise

    The 2008 Physical Activity Guidelines suggest doing 5 days of moderate intensity exercise each week or vigorous/high intensity exercise for about 20 minutes, 3 days a week, but how much you do is based on your fitness level and goals. It's good to work at a variety of intensity levels to tap into different energy systems and work your body in different ways.

    Too much high intensity exercise could lead to burn out or overuse injuries, so you don't want to do this kind of exercise every day.

    If you're a beginner, starting with interval training is a great way to get your body used to higher intensity exercise in short, manageable bites. There are ways to work hard while keeping things low impact if jumping isn't comfortable for you. Learn more about how to add intensity to your workouts and get the most out of your workout time.

    Examples of High Intensity Activities

    Some activities are naturally more intense than others, especially exercises that involve using large muscle groups like your legs. These include:

    A Word About High Intensity Interval Training, or HIIT

    High intensity interval training (aka HIIT) is where you work, then rest, then work again. HIIT workouts are defined as being done at 90-95% of your maximum heart rate.

    At this intensity, HIIT can yield what a 20 minute, 2-mille jog would yield.

    Now, if you do aerobic interval training, say on a treadmill, where you do intervals of 80-90% of your max heart rate for 10 minutes that is the equivalent of a 30-minute steady state workout performed at 75% of your maximum heart rate. Both are at a high intensity, but HIIT workouts and Tabata-style workouts should be performed at such a high level that the activity cannot be sustain for a long period of time. If you don't want to throw-up after 10 minutes, you aren't doing them hard enough to get the benefits these workouts tout. 


    US Department of Human Health and Services. 2008 Physical Activity Guidelines for Americans. Accessed Jan 5, 2010.

    Jakicic JM, Clark K, Coleman E, et al. American College of Sports Medicine. American College of Sports Medicine position stand. Appropriate intervention strategies for weight loss and prevention of weight regain for adults. Med Sci Sports Exerc. 2001 Dec;33(12):2145-56.

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