Beginners Calculating the Heart Rate Reserve By Wendy Bumgardner facebook twitter Wendy Bumgardner is a freelance writer covering walking and other health and fitness topics and has competed in more than 1,000 walking events. Learn about our editorial process Wendy Bumgardner Medically reviewed by Medically reviewed by Richard Fogoros, MD on November 08, 2015 Richard N. Fogoros, MD, is a retired professor of medicine and board-certified internal medicine physician and cardiologist. He is Verywell's Senior Medical Advisor. Learn about our Review Board Richard Fogoros, MD Updated on March 22, 2020 Print Johner Images/Getty The heart rate reserve (HRR) is the difference between a person's resting heart rate and maximum heart rate. It is the range of heart rate values that you can see for an individual, between the lowest they have at rest and the highest they can achieve through exertion. Heart rate reserve is used to calculate heart rate exercise zones by the Karvonen formula. In studies, the heart rate reserve has been found to compare well with the oxygen consumption reserve (VO2R) for estimating exercise energy expended at different exertion levels. Target Exercise Intensity The Karvonen Formula uses the heart rate reserve number before calculating heart rate percentage of maximum numbers for target heart rates. You need to know your resting heart rate by taking your pulse first thing after awakening and before you get out of bed. Then you need to know your maximum heart rate, which can be estimated by subtracting your age from 220 (classic Karvonen Formula) or 206.9 - (0.67 x age) with the updated formula. This formula may not be accurate if you are in very good aerobic condition for your age. So, athletes may use other methods to determine their maximum heart rate. With these two numbers, the Karvonen Formula is Exercise HR = % of target intensity (HR Max – HR Rest) + HR Rest. The middle term is the heart rate reserve, which is then multiplied by the percentage of target intensity desired, and then the resting heart rate is added back in. If you want to exercise in the moderate-intensity zone, the percent of the target intensity defined by the CDC is from 50% to 70%. Increasing Your Heart Rate Reserve Maximum heart rate is mostly age-based and difficult to change with exercise, with only small effects seen. The implications for heart rate reserve is that you would increase it most by lowering the resting heart rate. The resting heart rate is seen to be lowered by increasing cardiovascular fitness, although overtraining can result in a temporary increase in the resting heart rate. To achieve a larger functional heart rate reserve, the chief mechanism is to lower the resting heart by building cardiovascular fitness with activities such as brisk walking, jogging, running, cycling, and other endurance exercises. These cardio exercises challenge the lungs and heart and when engaged in regularly they build cardiovascular capacity. Was this page helpful? Thanks for your feedback! Get exercise tips to make your workouts less work and more fun. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Jackson, Andrew S. "Estimating Maximum Heart Rate From Age: Is It a Linear Relationship?" Med Sci Sports Exerc. 39(5):821, May 2007. Swain, DP. "Energy cost calculations for exercise prescription: an update". Sports Medicine. 2000 Jul;30(1):17-22. Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology. 2001 Jan;37(1):153-6. Zavorsky, GS. "Evidence and possible mechanisms of altered maximum heart rate with endurance training and tapering". Sports Med. 2000 Jan;29(1):13-26.