Yeah I’m not suprised one bit. If you wanna see accurate results stick with the chest strap. I wonder if Garmin has made some firmware changes recently?
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My wrist HR was definitely showing higher HR recently when I forgot to pair the strap to my replacement watch!
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Cardiac drift.
So watching my HR climbing 1 beat every 1-2km on my 15km run today got me thinking about cardiac drift.
How much does dehydration affect it?
And a high BMI/BF%?
Core temperature is the key contributor to cardiac drift…so dehydration must be considered a contributory factor…
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Makes sense. I try to drink on my long runs but I’m always a kilo lighter at the end at least. Will try harder.
what is a kilo as a % of mass and how long is long?
I’m talking in rough terms; today I was about 87kg in the morning, ran 30mins am, ate and drank in between, then 1h30 pm, was 86kg after the last run. Previous years I’ve weighed myself before and after runs and it’s generally true with a one hour run even if I drink on the run, I guess I just gush.
Long at the moment is 1h30-2h.
I have sometimes suspected my body offloads water for some other reason. My blood pressure drops significantly after a run too.
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I’ve found that after swimming, not sure if it’s the cold water? Never really checked after running or cycling.
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Why the double session - strategic?
not uncommon - post ex hypotension…
edited to add that if you feel faint or it drops too rapidly, go and see the Doc
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Strategic? Yes.
I have always struggled with run consistency and run volume. Also, last year I did it traditionally up to 4-5hrs running per week for a while but had some unspecified problem the doctors couldn’t diagnose that stopped my running volume for months.
I tried double single-sport days since last autumn, and I’ve found it’s much more enjoyable and much less stress to just have either running or cycling, unless it’s a brick day.
Also, when I’ve ran 21km in a day it’s much easier to finish and much less recovery time for the bike workout or swim the next day.
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Yep, am a big fan…
But it does depend on what you are training for…
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Just watching the boat race at the moment and they’ve got HRMs on the coxes of the 2 crews.
The Cambridge cox was up to 160bpm and the Oxford cox at 175 
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The little guy who shouts ?
175 bpm … that is mad ?!
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well I’ve heard of putting HRMs on athlete’s wrists, but this is next level.
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they are racing vicariously…
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Anyone looked at heartbeats per kilometre while running? I noticed a guy putting it on strava and seemed interesting.
For my last few runs I have multiplied average BPM from wrist HRM by time taken, to calculate total heartbeats per run. And then divided that by distance to get a figure for heartbeats per kilometer.
Obviously a bit of variation with terrain etc, but for my on road runs at upper Z2 pace I’m consistently hitting around 700 - 750 heartbeats per kilometer (Average 734, SD +/- 29).
Interestingly & I guess intuitively, on the runs that felt good the beats/km were lower.
Planning on doing a bit more running as training for a half mara over the next 3 months & might keep a check on this and hope it might come down a little (not to zero though)
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I did it that year when I went all in for the Schwiening method (well not just his obviously) of really high mileage at really easy pace. No speedwork whatsoever, but lots of heat forced work too (to get the HR up without running the legs into the ground).
A mate had been doing it for a couple of years, and he recorded that stat religiously. I did the same for my build into London 2017 I think it was. I was in cracking shape but ultimately picked up a niggle in the last few weeks that derailed it all.
If I remember correctly, the data nearly always saw a levelling of values for a few weeks, then there’d suddenly be this step change drop. Then it would level for a few weeks and you’d see another drop. I’ll see if I can dig out some of my old stuff. Purely out of interest, I don’t think it’ll add value to your experiment per se.
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OK That’s depressing me now.
Just found the one ‘session’ that I did, which was beyond easy running.
16kms at target mara pace, hitting 3.45/km average with an efficiency score of 672/km.
And to make it worse, that was on the Sunday of a 175 km week!!!
The weeks before being 161km, 112km, 75km, 165km!!
I was so fit then!!! (Probably over trained which caused the injury though as well)
Looks like the runs where I was going well were around the 700 beats/km mark
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Wow! I guess that explains where your pedigree comes from. Wasn’t following you on Strava then so had no idea you were such a regular mileage monster, thought you just rolled out of bed and did the odd 90 miler now and then!
Very interesting what you say 
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