u/Jaguarmonster

I used to run treadmill without any planning or wearables but I've recently moved to the countryside which has excellent outside running options (and much better air!), which led me to take running a little more seriously. I've bought a Polar H10 strap and a Coros pace 4 as my first wearables to get more insight, which has led me to discovering my HR behavior.

Long story short: my heart rate almost immediately goes up to high 160s low 170s, even with relatively low effort. On a social run with my girlfriend last weekend we ran an 80 minute 10k (with walking breaks) and my heart rate very reliably shoots up to 165-170 within minutes of holding a 6min/km pace despite still breathing through my nose the entire way through and not feeling tired at all. For comparison, the week before that I ran a 22min 5k which was moderately challenging and my heart rate is more or less identical to the 80 minute 10k ignoring breaks (~168). I've also ran a sub 20min 5k in March on the treadmill (before I had wearables so not sure what my HR was back then).

If I am just sitting in front of my desk on my pc my heart rate is in the mid 50s, but if I get up and go for a 20 minute walk (not run) outside it goes to 120, which I think is a bit odd. My friend, who has worse times across every distance and is also a bit heavier than me while being an inch shorter, doesn't get above 150 flat when doing casual 30min 5ks or 60min 10ks. Is this just kind of an individual thing?

I guess I am just wondering if anyone has similar HR behavior, or knows of someone who does or can offer more insights into it.

Extra info:

- yes I made sure the polar overrides the watch's HR, although the polar gives very similar results (I've tested both)

- on 4x4 intervals my HR goes significantly higher, capping out at 184 (I am 36yo so this is in line with what you'd expect)

- my HR recovers fast, within a minute I am going from high 160s to 120s

- I do not experience any distress during running whatsoever aside from what comes naturally with running, and am otherwise healthy

- I come from a bodybuilding background and still do typical bodybuilding-esque resistance training 4x a week, so I am a little heavier and more muscular than the standard runner (6'1 200lbs / 185cm 90kg), especially in the quads. Not sure if that matters.