Is Exercise at a High Intensity Always the Best?

Starting to move your body is the first step towards becoming fit. Furthermore, the intensity with which you do the movement matters just as much as its quantity and kind. Three main categories of intensity are used to describe exercise and physical activity: low, moderate, and high (sometimes referred to as “vigorous”). However, it can be difficult to pinpoint precisely which kind of activity belongs in which intensity category.

For instance, the 2020 guidelines on physical activity and sedentary behaviour published by the World Health Organization (WHO) suggest that adults with average physical fitness should engage in 150 to 300 minutes of moderate-intensity exercise per week, or roughly 21 to 43 minutes per day, or 75 to 150 minutes of vigorous-intensity aerobic exercise per week.1. However, how can you be certain that the activity you have chosen is actually vigorous enough? Is the intensity of your aerobic exercise too high? Is a vigorous workout always the best option, or may a decent, low-impact stroll suffice? Do beginners and fitness enthusiasts have to follow the same rules? So many inquiries.

Gaining an understanding of the meaning of each exercise intensity and how to organize your fitness regimen accordingly can help you get the most out of every workout. Experts in health and fitness were invited to deconstruct them, discuss their significance, and offer tips on how to incorporate them into your everyday routine.

An Overview of Intensity in Exercise

When you exercise, intensity is directly related to how hard you are working—or, more accurately, how hard your heart is working. There are two methods for testing the three levels, which go from easy to hardest: the “talk test” or heart rate monitoring.

The talk test is arguably the simplest method for determining intensity because it just asks you to rate how easy or difficult it is to talk while engaging in any given activity. According to William Smith, MS, NSCA-CSCS, author of Exercises for Cardiac Recovery, you can move while maintaining conversational skills when you perform low-intensity exercises.

You should not be completely out of breath when engaging in moderate-intensity exercise, but you will not be able to carry on a conversation as readily. There might be a little break in your words from sporadic, but controlled, deeper breathing. You will be unable to carry on a conversation at all, nor will you want to, if you are moving at a high or strong intensity.

Technically speaking, heart rate—or the number of times your heart pumps in a minute—can also be used to gauge how hard an exercise is. Heart rate monitors (which are typically included in smartwatches like the Apple Watch) make it easy to measure your heart rate both at rest and during activity. On the other hand, you can perform some traditional counting if you do not have a monitor. Simply locate your pulse on your wrist or neck, count the beats for ten seconds, and then multiply the result by six to get the beats per minute.

Recognizing Your Maximum Heart Rate and Exercise Intensity

With all of this information in hand, the next step is to determine your maximum heart rate (MHR), which is the maximal intensity you should be reaching when exercising.

“The calculation of exercise intensity is based on your maximal heart rate during physical activity,” explains Ben Walker, the owner of Anywhere Fitness in Dublin, Ireland, and a personal trainer. “Your body is working harder the greater the proportion.”

Subtract your age from 220 to find the maximum heart rate that your body should have.

For example, your predicted heart rate (MHR) would be 180 beats per minute if you were 40 years old. Now that you are aware of your own maximum heart rate (MHR), you may use it to gauge how many beats, based on the intensity of the activity, you should aim for. This is an explanation:

Minimal Intensity

Working at between 30 and 50 percent of your maximum heart rate is referred to as low intensity. Walker suggests multiplying your MHR by.30 and then.50 to find your heart rate range.

Using the previous example, multiply 180 by.30 (=54) and then.50 (=90) if you are 40 years old and your estimated MHR is 180 beats per minute. What was the outcome? When participating in low-intensity exercise, the heart rate of a hypothetical, healthy 40-year-old should stay around between 54 and 90 beats per minute. Low-exertion aerobic activities include low-resistance bike, gentle yoga, casual walking (where you can still carry on a conversation), and leisurely swimming laps. These activities typically entail repetitive movement at a slower, steadier tempo. You are not huffing and puffing, but you are in motion.

Mild Intensity

Your heart will beat slightly harder during moderate-intensity aerobic exercise, but not to its maximum capacity—roughly between 50 and 70 percent of your maximum heart rate. Walking or hiking at a quick pace, dancing aerobically, playing tennis in pairs, cycling (no more than 10 miles per hour, per the American Heart Association), and even hard yard or housekeeping are examples of common hobbies.

Elevated Level of Intensity

Lastly, training at 75 to 100 percent of your maximum heart rate (your heart should be beating between 135 and 180 beats per minute on average for a 40-year-old) is considered high intensity. According to Walker, this intense kind of exercise frequently entails brief, rapid-burst workouts where you must react quickly. You should be exerting a lot of energy, breathing loudly and quickly, perspiring, and unable to carry on a conversation. For example, you could be playing tennis singles, running, cycling at ten miles per hour or more, jumping rope, climbing the stairs, or engaging in high-intensity interval training.

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