Tuesday, September 2, 2014
Heart rate while exercising
I regularly exceed my maximum heart rate (as most charts say for age, 20 minutes or more) while using rowing or cross-training machines. Am I causing damage to my heart muscle by this practice?
First, the normal caveat... I can't really completely answer your question without A LOT more information and without having examined you. I can speak in some generalities however. First and foremost, if you are asking this question because you are having any cardiac symptoms during exercise, then you should discontinue your exercise program and see your physician immediately. Cardiac symptoms would include things like:
- chest pain
- difficulty breathing
- blurry vision
- abnormal heartbeats
In exercise physiology, we ESTIMATE someone's maximal heart rate during voluntary exercise as being 220 - age. For example, if you are a 40 year old, we'd estimate your maximum heart rate limit as: [220 - 40 = 180]. So we'd expect that our hypothetical patient would not be able to exercise hard enough to get his/her heart rate above 180 regardless of how hard they try.
This is an ESTIMATE and not really an actual determination of our hypothetical patient's maximum heart rate. To actually determine it, we'd have to get him/her into the lab and perform a pretty strenuous graded exercise test.
Most exercise guides use this maximum heart rate estimate as the ceiling for exercise and make exercise recommendations based upon it. For example, the American College of Sports Medicine guidelines for improving fitness and body composition include exercising 3 - 5 times per week, for 20-60 minutes at a time, at an intensity that is AT LEAST 55 - 65% of your maximum heart rate. This THRESHOLD for our hypothetical patient would be to exercise at a heart rate of AT LEAST 99 - 117 beats per minute. [180 x 0.55 = 99, 180 x 0.65 = 117)
The ACSM also indicates that you can gauge your exercise intensity using the "talk test". If you are exercising so hard that you can't maintain a conversation with your exercise partner, then you are exercising too hard.
Again, without a lot more information I can't speak to whether you are harming your heart muscle through exercise, but if you are healthy, then going a little above the threshold value is perfectly fine. However, the ACSM and other organizations strongly recommend that you have a complete physical exam prior to beginning a strenuous exercise program.
Mark A Merrick, PhD, ATC
School of Health and Rehabilitation Sciences
The Ohio State University