To determine your maximum heart rate, subtract your age from 220. This number represents how many times your heart should beat per minute at its maximum rate. Multiply that number by 0.6 and 0.85 to determine the range of heart rate to strive for. Healthy people can build up gradually to be able to sustain this heart rate for 30 to 45 minutes at least 3 times a week to build aerobic fitness.
Update Date 3/20/2011
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.