Exercise intensity refers to how hard the body works while engaging in physical activity. While any exercise is better than none, engaging in moderate to high-intensity aerobic activity several times per week helps strengthen the heart and lungs, and also helps individuals control their weight and body fat percentage, lowering the risk of certain diseases and medical conditions. There are several ways to monitor exercise intensity, including monitoring the heart rate, the ability to speak while working out, and the overall feeling of intensity during an exercise session.
Monitoring the heart rate to ensure it falls within the target zone is one of the best ways to monitor exercise intensity. An individual's maximum heart rate in beats per minute is 220 minus his age. Exercising to keep the heart rate between 50 and 80 percent of the maximum heart rate is ideal. People who are just beginning an exercise program should start with activities that keep their heart rates on the lower end of the target heart rate zone and should gradually increase the intensity of their workouts to progress toward working out at the upper end of the target zone.
Testing the ability to speak is a quick and easy way to monitor exercise intensity. Being able to sing indicates very light or low-intensity exercise. Participating easily in a conversation is doable with moderate-intensity workouts. Individuals who cannot say more than a few words without pausing for a breath are exercising at a high intensity.
If it is not practical for an individual to check his heart rate or perform the speech test, or if he simply wants an immediate indicator of exercise intensity, certain physical clues can give a general impression of how hard a person is working out. Breaking a sweat is one of the most obvious indicators of intensity. Sweating after about 10 minutes of exercise typically signifies moderate intensity, while working up a sweat within a few minutes usually indicates vigorous exercise. Paying attention to breathing rates is also important. Slightly quicker breathing may point to moderate-intensity exercise, while deep, short breaths are indicative of vigorous exercise.
Certain health conditions, injuries, and medications can affect how hard a person should exercise. People planning on beginning or changing their exercise programs should discuss their plans with their doctors to ensure they are working out safely. Any exercise that causes severe shortness of breath, intense heart palpitations, or other extreme symptoms should be stopped immediately until the individual can consult with his doctor.