To reap the benefits of exercise, you don't have to pound the pavement or participate in a vigorous fitness class. Low-intensity forms of exercise, such as walking, biking and swimming, offer heart-healthy aerobic activity and can help reduce stress and boost your mood. While you do have to exercise longer to achieve a calorie burn comparable to more vigorous types of exercise, low-intensity exercise generally carries a lower risk of injury and overexertion, which can be especially helpful for exercise beginners.
Measuring Exercise Intensity
There are several ways to gauge whether you're exercising at a low-, mid- or high-intensity level. The simplest test is to consider how you feel. If you have no noticeable changes in your breathing, can carry on a normal conversation and are not sweating, you are exercising at a low-intensity level, according to MayoClinic.com. Another, more precise method of measuring exercise intensity is to keep track of your heart rate, which should be between 40 and 50 percent of your maximum heart rate during low-intensity exercise. According to the American Council on Exercise, you can easily determine your maximum heart rate by subtracting your age from 220.
Calorie output during exercise depends on several factors, including your intensity level, weight and the amount of time you spend exercising. Walking is low intensity and low impact, making it a great option for people of all ages and skill levels. A 130-pound woman can expect to burn an estimated 118 calories while walking for one hour at a casual 2-mph hour pace. A 150-pound woman can expect to burn 136 calories. If she increases her speed to a 3-mph pace, a 130-pound women will burn 195 calories, while a 150-pound woman will burn 225. When increasing the pace, however, make sure to monitor your heart rate so it does not exceed the targeted range of 40 to 50 percent.
Casual swimming offers a higher calorie output than other forms of low-intensity exercise. A 130-pound woman can expect to burn 206 calories after 30 minutes of casual swimming and 413 calories after an hour, while a 150-pound woman can expect to burn 238 and 476 calories, respectively. Again, it's important to pay attention to your heart rate to ensure you're exercising at an appropriate level. Because exercising in water lowers your heart rate, the University of Maryland Medical Center recommends that swimmers use a heart rate that is 75 percent of their maximum and then subtract 12 beats per minute to reach their target heart rate.
Calorie output when biking at a 5.5-mph pace is fairly comparable to the calorie output achieved when walking at a moderate pace. During an hour bike ride, a 130-pound woman can expect to burn 236 calories, and a 150-pound woman can expect to burn 272 calories. If you're pregnant and choose to bike rather than walk or swim, you're advised to use a stationary bike to eliminate the risk of injury from falling off a moving bicycle.
Not all yoga workouts are created equally. Hot yoga and power yoga classes are considered higher intensity and are not recommended for everyone. Select a beginner yoga class if you wish to exercise at a lower intensity. A 130-pound woman can expect to burn 154 calories during an hour of gentle yoga, and a 150-pound woman can expect to burn 178 calories.