You know your heart rate skyrockets during burpees or when a "we need to talk" text pops up on your phone (and if you're serious about fitness, you may even train according to your heart rate).
But how often do you pay attention to your resting heart rate (RHR), which is your heart rate when you're 100 percent chill?
Well, the latest research from Fitbit might convince you to pay attention. The wearables company tapped into their giant user database of more than 108 billion hours of heart-rate data to analyze resting heart rates around the world. Of the 15 different countries the company reviewed, the U.S. and Singapore had the highest RHR at 65.9 beats per minute (bpm) while Italy had the lowest at 61.8 bpm.
And remember that, in this case, higher is not better.
Resting Heart Rate 101
Here's a little refresher: Your RHR is an important number because it's a great indicator of your overall health and fitness, namely your cardiovascular health. Essentially, the lower the number, the more efficiently your heart is working, says Scott McLean, Ph.D., principal research scientist at Fitbit. "You have to pump a certain amount of blood around the body per minute," says McLean. "If your heart is larger, stronger, and the arteries are clear and working well, you'll pump more blood to the body during each beat, which means that, per-minute, you'll need fewer beats to make that happen," he says.
While an RHR anywhere between 60 and 100 bpm is normal for most people, according to the American Heart Association, a higher average RHR in the U.S. is a negative reflection of the nation's overall health. "If you think about it, the U.S. also seems to be ranked highly for a lot of the variables that negatively affect resting heart rate: overall stress, work-related stress, obesity, poor diet, inactivity, etc.," says McLean.
The few points between the U.S.'s (65.9) and Italy's (61.8) scores may not seem like a huge difference, but those few bpms are significant over a lifetime.
"We pulled from so much data that even though the difference seems small, it's actually statistically significant and it can also be clinically significant," says McLean, which basically mean the difference is important for both research and IRL health concerns. "Even a 3 or 4 bpm difference in resting heart rate can have a huge impact over time on someone's general health, well-being, and morbidity. In fact, resting heart rate has been linked directly to your risk of death." Paying attention now?
The biggest culprits that hurt your RMR score? Lack of sleep, tobacco use, being overweight or obese, dehydration, and stress, says McLean. The easiest way to improve (i.e., lower) your RHR is to literally get your blood pumping. Your heart is a muscle, and if you want to get it in good shape, you have to work it out. (Yes, that means cardio.) However, he says that you can see significant improvements in your RHR just by increasing your overall activity levels each day—no marathon training or crazy HIIT workouts necessary.
Fitbit's research yielded other interesting results, too. Resting heart rates gradually increased with age up until you hit the 40–49 age group (which had the highest RHR for both sexes), then started to decline again. Because Fitbit's huge selection of RHR data is the first of its kind, this finding is pretty novel. Researchers aren't entirely sure why your RHR goes down after peaking sometime in your 40s, although McLean says it may have to do with age-related changes in heart mechanics.
The health tech company also noticed that female users had a higher average RHR overall than male users by 3 bpm. Before you panic, listen up: This doesn't have any health indications, but rather is a result of anatomical differences in heart size and hormone levels. (Really, don't worry: Women consistently live longer than men.)
How Does Your Resting Heart Rate Compare?
The best way to get your RHR is to wear a heart-rate monitor like Fitbit while you sleep. No device? To measure it yourself, find your pulse on your wrist first thing in the morning (without an alarm clock or other stimulation or distractions). Count the number of beats in 30 seconds and multiply that number by two. Consider making note of your RHR on two or three different mornings and averaging your results, says Cary Raffle, a certified personal trainer and exercise science pro in NYC, as we reported in How to Find (and Train In) Your Personal Heart-Rate Zones. This can ensure you didn't just record a number on a particularly stressful day or after a rough night's sleep.
Keep an eye on your RHR over time to know what's normal and abnormal for you, says Harley Pasternak, celebrity trainer and Fitbit ambassador, in a press release. That way, you can monitor how your health is changing, and know if you're ever in a situation where you need to seek advice from your doc.
And, post–cardio sesh, why not take a cue from RHR winner Italy and stock up on red wine and pasta, and treat every day like vacay.