The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


How Long After Working Out Does Your Heart Rate Return to Base?

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Monday, Dec 14, 2020

Omega-3 Fatty Acids Are Related to More Rapid Heart Rate Recovery

Those of us that are health conscious are well aware that poor cardiorespiratory fitness (CRF) is a strong predictor of conditions such as cardiovascular disease, type 2 diabetes, and some cancers. The gold standard for measuring CRF is a maximal treadmill exercise test performed in a clinical setting.

Heart Rate Recovery (HRR)

In recent years, heart rate recovery (HRR) from maximal exercise has also been identified as an important cardiovascular health measure. HRR is defined as the difference between maximal exercise heart rate and the heart rate at a given time point following exercise (or how quickly does your heart rate drop at a certain time after stopping exercise).

For example, as shown below on the left side of the Figure, if heart rate during maximal exercise is 190 beats/min and heart rate at the 1-minute mark of active recovery is 180 beats/min, then the HRR is 190 – 180 = 10 beats/min. As a reference point, a HRR of <12 beats/min at minute 1 of recovery is considered poor/high risk. On the right side of the Figure, we see that the maximal heart rate is 190 beats/min and heart rate at the 1-minute mark of active recovery is 160 beats/min, so the HRR is 190 -160 = 30 beats/min. This is an excellent/low risk HRR.

Thus, the more rapidly the heart rate decreases following exercise, the lower the risk for future cardiovascular events.

Omega-3 Fatty Acids

Most of us are also aware that omega-3 fatty acids, more commonly known as ‘fish oils’, are found in fatty fish as well as in supplement form, and have been shown to be beneficial to cardiovascular health. The Cooper Clinic measures omega-3 fatty acid levels in the blood using a method called the Omega-3 Index (O3I). The O3I is a measure of what percentage of fatty acids in red blood cells are omega-3’s. 

There are 3 categories for the O3I: low is <4%, normal is 4-8%, and optimal is >8%.


The Cooper Institute Study 

In a recent study by The Cooper Institute, we examined the relationship between the Omega-3 Index and HRR at 1, 3, and 5-minutes post-maximal exercise in a group of 13,912 healthy men and women with an average age of 50 years who were examined at the Cooper Clinic between 2007 and 2019. This study showed a significant relationship between the O3I and HRR in both men and women. The higher the Omega-3 Index, the more rapid the HRR. The authors concluded that higher O3I levels are related to a more rapid HRR in healthy men and women.

Importantly, these results were independent of the subjects’ level of cardiorespiratory fitness.


How to Improve Heart Health

While cardiovascular disease (CVD) is the leading cause of death for U.S. men and women, there are several lifestyle habits that can lead to a decreased CVD risk. These include regular physical activity, avoiding tobacco, achieving a reasonable body weight, and consuming a healthful diet.

Results from the current study reinforce recommendations from the American Heart Association to consume at least 2 servings of non-fried fatty fish per week in order to improve heart health.



Farrell, S.W., DeFina, L.F., Tintle, N., Barlow, C.E., Leonard, D., Haskell, W.L., Berry J.D., Willis, B.L., Pavlovic, A., Harris, W.S. Higher omega-3 index is associated with more rapid heart rate recovery in healthy men and women. Prostaglandins, Leukotrienes, and Essential Fatty Acids. December, 2020.