Thursday, March 17, 2011

Resting Heart Rate Research

In the beginning of February, I launched an indoor cycling class at The Landings Club called “Heart Rate Ride.”  Training within certain heart rate boundaries can result in very specific health and fitness benefits.   So the cyclist, who is strongly advised to wear a chest-strap heart rate monitor in class, learns those boundaries which create a health-, or an endurance-, or a performance-related response.  Every rider also learns how to use their heart rate monitor to measure their own resting heart rate (RHR), and to incorporate the RHR to find their estimated target heart rate range using the newly revised Karvonen formula.  They can apply their target heart rate range to all their cardio-vascular exercise and activities, and manipulate their intensity levels to better reach their fitness goals.


Upon learning their RHR, most clients will come and ask me, “Is that good?”  And my honest answer, up until now, has been, “Well, it is all relative, I’ve never heard of a definite link between RHR and heart health.  But as your fitness improves and your heart grows stronger, your RHR usually decreases, and that, relatively speaking, is good.” 

Until now.  Research published in American Heart Journal lends some long awaited clarity to the question, “What’s a good resting heart rate?”   The study tracked over 21,000 middle-aged adults for an average of 12 years, which is a nice, long retrospective study period.  The results indicated that women with a RHR above 90 beats per minute were three times more likely to die of heart disease during the study than those with a rate below 60 beats a minute. Men with rates above 90 were twice as likely to die of heart disease.  The results were consistent when adjusted for age, gender, total cholesterol, physical activity (categorical), systolic blood pressure, body mass index, and high-density lipoprotein cholesterol (aka “good cholesterol”).

There’s a little more food for thought in here.  Women’s heart rates are typically higher than men’s, because our hearts usually aren’t as large and therefore have to beat more often to pump the blood around.  Look at those numbers in the paragraph above with that in mind.  Women might not have as far to climb to get over 90 beats per minute, and likely have to work harder to get the heart strong enough to drop below 60 beats per minute.  So, ladies and gentlemen, get with me here, we really need to get fit and keep those hearts strong to get that RHR number down.

Reference: Am Heart J. 2010 Jul;160(1):208. Laatikainen, Tiina