Aerobic exercise, such as jogging, cycling, swimming, and hiking, is a fundamental way to maintain cardiovascular and general health. The intensity of your aerobic exercise is important because it determines how much time you should spend training to reap its benefits.
As an exercise science researcher, I support the American College of Sports Medicine’s recommendations for at least 150 minutes of moderate-intensity aerobic exercise and 75 minutes of vigorous-intensity exercise per week. But what does exercise intensity mean?
There is a linear relationship between heart rate and exercise intensity; as exercise intensity increases, heart rate also increases. Heart rate zone training, which uses heart rate as a measure of exercise intensity, has grown in popularity in recent years, due in part to the proliferation of wearable heart rate technology.
There is usually a problem with how we describe the intensity of exercise, since what is “vigorous” to one person may be “moderate” to another. Heart rate zone training attempts to provide an objective measure of intensity by dividing it into different zones. However, heart rate can also be affected by temperature, medications, and stress levels, which can affect your measurements during exercise.
Heart rate, exercise intensity
The gold standard for determining the intensity of aerobic exercise is to measure the amount of oxygen consumed and the amount of carbon dioxide exhaled. However, this method is cumbersome as it requires wearing a breathing mask to capture breathing gases.
A simpler method is to predict the person’s maximum heart rate. This can be calculated using the equation: 220 minus the person’s age. Although there is debate about the best way to calculate maximum heart rate, researchers suggest that this method is still valid.
The American College of Sports Medicine outlines five heart rate zones based on a person’s predicted maximum heart rate. Zone 1, or very light intensity, corresponds to less than 57% of your maximum heart rate. Zone 2, or light intensity, is between 57% and 63%. Zone 3, or moderate intensity, is between 64% and 76%. Zone 4, or intense intensity, is 77% to 95%. Zone 5, or near maximum intensity, is between 96% and 100%.
However, other organizations have their own exercise intensity measures that vary in scope and description. For example, Orange Theory describes Zone 2 training as 61% to 70% of your maximum heart rate. To further complicate matters, companies that make heart rate monitors set high thresholds for each zone.
For example, Polar’s Zone 2 is 70% of your maximum heart rate, while the American College of Sports Medicine recommends a Zone 2 of up to 63%.
Heart rate zone adaptation
Zone training is based on the idea that how the body responds to exercise is determined, at least in part, by the intensity of the exercise. These adaptations include increased oxygen consumption, important cellular adaptations, and improved athletic performance.
Zone 2 has received a lot of attention from the fitness community due to its potential benefits. Performance coaches describe Zone 2 as “light cardio.” Here, the intensity is low and the body relies primarily on fat to meet its energy needs. Fats provide more energy than carbohydrates, but they deliver it to your cells more slowly.
Because fats are more abundant in the body than carbohydrates, the body responds to the cellular stress exerted on muscle cells by increasing the number of mitochondria, the energy-producing components of cells. By increasing the number of mitochondria, your body may be able to burn fat more easily.
At the other end of the spectrum is high-intensity interval training (HIIT). These workouts include short periods of high-intensity exercise, such as sprints or cycles, for 30 seconds to 1 minute, followed by lower-intensity activity. Repeat this 6 to 10 times.
During this type of high-intensity activity, the body primarily uses carbohydrates as a fuel source. During high-intensity exercise, the body preferentially uses carbohydrates because the energy demand is high and carbohydrates provide energy twice as quickly as fat.
Some people who exercise to lose fat avoid high-intensity training because zone 2 is considered the “fat burning zone.” This may be a misunderstanding.
Researchers found that high-intensity interval training resulted in similar increases in mitochondrial production markers compared to longer, moderate aerobic training. Studies also show that people who exercise at high intensity build muscle and improve insulin resistance and cardiovascular health just as much as those who exercise at moderate intensity, and their gains are faster. I am. The main trade-off was discomfort during high-intensity exercise.
moderate or high intensity exercise
Exercisers may be confused about what to do, as guidelines regarding heart rate zones vary and there is conflicting evidence about the potential benefits of training in each zone.
The most important factor to consider in order to reap the health benefits of exercise is adherence to an exercise routine, regardless of intensity. The body adapts equally to moderate and high-intensity exercise, so a person can choose which intensity they like the most or least.
Please note that the American College of Sports Medicine’s recommended exercise intensity falls under moderate intensity. This corresponds to zone 3, or 64% to 76% of your maximum heart rate. This range can only be met at the upper levels of most Zone 2 workouts. If you’re not getting the results you want from your Zone 2 workouts, try increasing the intensity until you reach a moderate level.
A commonly reported reason for not exercising is lack of time. For those short on time, high-intensity training is a good alternative to steady-state cardio. If you find this type of high-intensity exercise uncomfortable, you can achieve the same benefits by doing moderate-intensity exercise for a long period of time.
Jason Sawyer He is an associate professor of exercise science at Bryant University.
This article was first published conversation.
