Aerobic Workout Calculating intensity

For cardio work to be effective you must work at a level of intensity higher than when the body is at rest for at least 20 minutes three times a week. Aim to stay at around 60–75 percent of your maximum heart rate. To calculate your heart rate, buy a monitor or exercise your brain by counting your pulse. Find your pulse at the side of your neck with your first two fingers. Count the beats over six seconds. Multiply by 10 to find out how many beats per minute (BPM). This is your heart rate. A typical 35 year old should keep her heart rate during 20 minutes cardio work between 111 and 138 BPM. This drops to 102–127 BPM by age 50 and to 93–115 BPM by 65.