How hard do you exercise? Its probably not as vigorously as you think, suggests a new Canadian study published in PLOS One. Researchers tested 129 sedentary volunteers, ages 18 to 64, and found that most overestimated how intensely they were exercising. When asked to walk at the lowest intensity they thought qualified as moderate, only 25% got their heart rates high enough; most barely exceeded a leisurely stroll. Few hit 65% of their maximum heart rate (in beats per minute, 220 minus your age) when told to exercise moderately. Even fewer achieved more than 75% when instructed to amp up to vigorous exercise.
Moderate exercise is considered 64% to 76% of your maximum heart rate; you should be able to talk but not sing. Vigorous exercise is between 77% and 90% of maximum beats per minute-a panting pace where you shouldnt be able to say more than a few words.