When I first got my Fitbit tracker, back when I first began seriously training as an endurance runner, it initially showed my resting heart rate’s (RHR) beats per minute (BPM) in the high 60’s.
As I continued training, my resting heart rate came down and settled around the high 50’s. Sometimes it would drift up, but often it came back down to around that number.
I noticed that generally it would increase during times of substantial stress, and that it would decrease with proper rest and exercise.
Suddenly, during the late summer and early fall, my resting heart rate started slowly climbing. Suddenly it settled into the mid 60’s and nothing I thought to do could bring it down. Resting more didn’t help. Eating more or less or better didn’t help. Exercising more or less didn’t seem to help.
At some point, not at the same time as last year, it began to come down again and settled around the high 50’s, low 60’s.
And then it came back up again. It was in exploring a variety of factors that finally taught me what elevates an athlete’s heart rate, and it turns out often times there’s nothing random about it.
There’s all sorts of general reasons experts and amateurs alike will give for elevated heart rates that are so tone deaf that their advice might as well have come out of an old library book.
From experience, myself and others who also seriously train, from the track records of all involved… here are the likely reasons your resting heart rate is going up, in an arguable but roughly accurate order of importance:
You’re tired enough that you need to take a break
You are probably working on a lot, dealing with a lot, and stressing over a lot. Your resting heart rate isn’t going to lie to you, similar to how your weight isn’t going to lie to you when you overeat continuously over a period of time. If the bill is starting to pile up on your overall stress levels relative to the amount of recovery you’re getting, then your resting heart rate is going to elevate slowly.
Find some way to scale something back on your to-do list or calendar. At the very least, start carving out time to do nothing, to worry about nothing, to get some quality sleep, and so on. This is your dashboard-light warning that you need to fix something or bad things will happen, like many of the below issues.
You’re dehydrated
Stressed out or not, busy or not, overwhelmed or not… a lot of people don’t get enough water in their day. Many don’t even think about water consumption, and the lack thereof is another biological bill that begins to pile up and increase your resting heart rate.
Even with those who do, maybe they carry a 16oz bottle or something and make sure to drink it, but that’s not as much as they probably need. Or maybe they drink a lot of coffee or soda or energy drinks that sap water content from your cells. Or maybe they eat a lot of high-sodium processed food, which leeches consumed water to buffer now-inflamed cells and causes extra water retention… while still starving the cells that need water of that water.
On a more practical level, as you slightly dehydrate more and more, your blood viscosity (thickness) begins to increase, and your heart has to work more to keep it pumping. So your resting heart rate goes up.
This is easier to address. Drink some clean water. Make a point to drink a few cups per day. Eat a clean diet. Take it easy on the diuretic non-water drinks, and certainly avoid processed beverages like soda or alcohol.
You’re getting sick
The first harbinger of trouble with an illness is an increasing resting heart rate. You may or may not feel tired or otherwise creaky, but you may notice your resting heart rate starting to creep higher with no other explanation. Often, your body is starting to fight off an illness whose symptoms you may not be feeling yet.
As always, take your vitamins, get good sleep, and eat clean and healthy. If you’ve fallen off of that in recent days, consider this your warning of trouble and get back to it.
Hint: Some of the productive whole food remedies you’d turn to when ill, like eating copious amounts of soup or garlic, might be a good idea right now. They are eaten because they help flush the body, and in turn the illness in question. Perhaps you could clear it now before it becomes a festering mess throughout your body.
You’re heavily training and/or overtraining
How many miles have you been running recently? Any hard or long workouts? Mixing in other types of workouts, like circuit training, strength training, workout classes, rec sports, etc?
If you’ve been training a lot lately, your elevated heart rate is probably just your body’s dashboard-light going on about struggling to handle it.
Kick it up a notch on your recovery habits. Make sure you’re getting good sleep. Eat a robust, clean diet between workouts, and get quality protein/carbs in within a couple hours of workouts. Recover as hard as you’re training: Build in days or time blocks where you do nothing but sit/lay and relax for a while.
You’re hot
Another stressor to the body is heat. Thermoregulating the body becomes harder when it’s particularly hot outside or inside. Part of your circulation system’s job is to cool you when it’s warm. If your heart rate is up and it’s hot, it’s probably because your body is catching up to the hot temps.
Cooling off is easier in some places than others. I know in places like Seattle or Chicago a lot of homes and places do not have central A/C, and it can get pretty muggy in summer. Consider a cold shower or bath if you simply cannot get away. Otherwise, pound some cold (healthy) beverages, use or get within air conditioning however much you can, and try to cool off a bit. Maybe also scale back your training a bit or move it to the early morning or evening if you aren’t already training then.
You’re too hungry too often, or at the wrong times
This can especially be true if you’re having trouble getting to sleep. Going to bed hungry can not only keep you awake, but your body will feel unusually revved up and warm. This is your hungry body’s sympathetic nervous system responding to a need for food by elevating your heart rate.
Barring that, depending on your eating habits, perhaps you’re hungry throughout significant portions of the day.
In the morning, on the tail end of an intermittent fast, your body may react well to it. Coming off a workout or a lot of stress or physical work, or having one of those stretches in midday after a morning meal, this can instead stress the body and produce an elevated heart rate.
If you find you’re not eating regularly, then start eating regularly. Carve out time and take a stand at home/work if you need to in order to carve out time to do it.