Go with the heart

If you’ve recently begun working out, especially focusing on cardio exercises, you may be wondering how hard to push yourself. One good gauge is to first determine your maximum heart rate. According to the Mayo Clinic, healthy adults can figure out that rate by subtracting their age from 220. For example, a 40-year-old man’s maximum heart rate clocks in at 180 beats per minute. For moderate intensity, aim for 50 percent to 70 percent of your maximum heart rate. For vigorous exercise, go for 70 percent to 80 percent of the maximum. In the case of that 40-year-old man, a goal of 80 percent would mean a target heart rate of 144 beats per minute. Exercise newbies are encouraged to aim for the low end.

Source: mayoclinic.org