Exercise & Heart Rate Variability


The increased effort and higher demands placed upon your body during exercise will always result in an increased heart rate. This increase in your heart’s beats per minute is a necessary response to supply oxygen-rich blood to your working muscles. There can be a great deal of variability in heart rate from person to person.

Heart Rate Standard

Before looking at variability in your heart rate during exercise, first find a standard to help you gauge your heart’s effort. Your starting point is the classic formula for finding your maximum heart rate when exercising: subtract your age from 220 to find your max heart rate. So if you are 50 years old, for example, your max heart rate is 170. Once you have this number, you can start investigating any variability.

Variability Factors

Once you have established your max heart rate, you need to account for other factors that may create heart variability. The book “Advanced Marathoning” points out that hot air temperatures and wind can create harsher conditions that result in an increased variation–by five to 10 heart beats–of your heart rate. Dr. Tim Noakes states that your max heart rate can also vary due to endurance training as well as heart disease.

More Factors

Dr. Jack Daniels cites a host of other factors that promote heart rate variability: exercising indoors with little air movement and warmer temperatures, hilly terrain, age, overall health and fitness level, and elevation. All of these factors have to be accounted for as you work out and try to get a good gauge of your effort.


A racing or irregular heart beat is called an arrhythmia. The American Heart Association states that 2.2 million Americans live with atrial fibrillation, a form of arrhythmia. If your usual training heart rate is 145 beats per minute, and it suddenly spikes to 195 for a few minutes or longer, or continues to race at this higher rate after you stop exercising, this indicates a bigger problem. If you experience this type of extreme heart rate variability, stop working out immediately.

Expert Insight

The American Heart Association’s suggests that millions of Americans have experienced some form of heart fluttering or arrhythmia, especially as they get older. Minor arrhythmia is common, but if it is persistent, especially when exercising, visit your doctor for peace of mind and treatment, if necessary. Normal heart rate variability should not stop you from exercising regularly.

About this Author

Karl Gruber has been a freelance writer for 25 years, penning articles in various publications in Central Ohio. From 1996 to 1997, he successfully ran 52 marathons in 52 weeks. Gruber has also written a book about his marathon running, a sport he also coaches and competes in. He holds a Bachelor of Arts in communications from Ohio State University