High heart rate despite runs being easy

how are you measuring your heart rate?

wrist-based monitors are not always very accurate. if you are using one, I recommend confirming that your heart rate actually is as high as you think it is. try measuring with a chest strap, or manually.

This. Some people can never get accurate data from a wrist monitor. Sometimes it picks up your tempo. You probably aren't anywhere near 170 at that pace.

Maybe iron deficiency? I had a teammate who had a very similar issue, and once he realized he had an iron deficiency, pretty much all of his issues went away. Might be worth checking out

my HR is like this too. I know the watch is inaccurate. I'd go by effort.

Yep, measure with a strap OP. There are mid-d types on low mileage who run at a decently high HR a lot of the time. Would still be very surprised if you were 170+ @ 8:30/mile.

I just posted asking a very similar question before seeing yours. I’m only going into 10th grade though. Has your hr always been high during easy runs or just during the last year? Mine has always been on the high end though my race times are decent. What kind of mileage do you do?

Make sure there are no nutrient deficiencies, common ones include magnesium, b-vitamins, zinc, vit k2 etc. Also make sure that your breathing is relaxed, easy runs should be relaxed and effortless, breath more slowly

Everyone has different max HR and HR zones. It's not completely unprecedented to have an large easy run zone (zone 2 in 5 zone model) up to 180 and have tighter upper zones than someone with a lower max HR. Have you looked into trying to find your max HR or estimate of your LTHR range? (just saying 170 is limited without these values) If a little fatigued, my HR can come within 10 bpm of my LTHR despite going excriciatingly slow.

As this poster points out, your HR is very specific to you. If your max is somewhere near 220, then it's not a stretch to think that 170 could be an easy intensity.

However, every teenage runner I've ever known has done their easy runs too fast. There really isn't any advantage to this, but there certainly are a lot of risks. So, it's better to be on the safe side.

The old chestnut of doing your easy runs at least 2 minutes per mile slower than your 5k pace is worth sticking to.

You could have hypertension or pulmonary hypertension(hypertension in the lungs). Essentially reduces bloodflow to lungs and body and the heart beats faster to compensate. Can be completely genetic if your an outlier. High salt diet, little iron are some of the other possibilities. What is your resting HR?

Throw your heartrate monitor away and learn to run by feel. Easy is a feel, not a heartrate. How does your body FEEL?

Cadence lock.