Effects of rumination and anxiety over your heart rate
Note: the article below doesn’t try to mimic a scientific experiment, but it’s the result of constant observation of my heart rate variation correlated with certain events (actually, thoughts) .
Since the pandemic started, and especially after my episode of Covid-19, I paid much more attention to monitoring the HR zones when I run. I always measured my HR during runs, but now I started paying more attention to keeping it low (at least for a while). As devices for measuring my heart rate, I use a Polar H10 strap and a Polar Verity Sense monitor, both of them, but especially H10 being well regarded for their accuracy. I gave up on trusting my watch optical HR sensor ability regardless of the brand – my Garmin Fenix 7X is too heavy to be so great at measuring HR, especially during more intense workouts and the Polar Vantage V2, even if it is lighter, isn’t as reliable as a chest strap or a oHR sensor on your upper arm.
When I tried to follow the structured workouts based on heart rate zones, I became more aware of the challenges to keep your heart rate low while running (where low is relative to myself, because everyone is different – for example, my Zone 1 means up to 139bpm), every source of stress being responsible for a shift upwards in beats per minute. My usual outdoor running space is pretty flat, I mean it only varies 8-10 meters over 10km, which is kind of close to a measurement error margin – so it should be pretty easy to keep your pace, power and HR steady over a long(er) period of time (yes, I know about cardiac drift – it’s nicely described here).
I’m not a fast runner by any means, but I’ve been running for some years now and I have a decent volume of weekly running for a recreational runner (between 45 and 60km/week), so I consider my fitness level not being an important element in the situation described below.
What I noticed while running steady (a building base run) is that being mindful keeps HR steady low, whereas rumination and anticipatory anxiety raises the HR level with 8-10bpm. It was as simple as that … when I was present, minding the early day lights, smells or surroundings, my heart rate stays stable low, but when I engage in rumination or possible intensive future scenarios, my heart rate goes up 8-10 bpm. And that’s not happening once .. I can do it several times during a run, when I’m “fighting my daemons”, my body reacts similar to “fight or flight” situations and my HR raises … if I notice that and I stop it, focusing on my breath, on the lights or the smell of the surroundings being more connected, my heart rate will go back down.
For example, during a steady run on my usual course (7.39km, average gradient 0.19%, cardiac drift 0) I noticed my mind drifting to situations that generated anxiety and raised sharply my heart rate, only to come back low after I refocused on myself – no other factors involved.
I similar spike in HR you may see when you’re really in a situation perceived as dangerous – for example, when two stray dogs were following me closely and I had to turn back to them to drive them away, a explainable rise of heart rate happens:
Based on my observations, the impact of rumination and future scenarios on the heart rate is in my case 6-10 bpm and it’s easier to observ during steady low pace runs, but it’s only another proof of how much we can affect our entire body just with our thoughts.
For those interested in the correlation of HRV and anxiety/rumination/depression, you can find some studies here and here.
As we (well, most of us) are not measuring constantly our heart rate when we are engaged in different activities, it’s not easy to quantify the impact of rumination and anticipatory anxiety over your life .. at least not until those become obvious.
Yet another argument to exercise (outdoor preferably) and be more mindful.
Happy running and enjoy your life!
Liviu Nastasa 
What a great topic. Thanks for sharing. I can relate to that topic as well.