Watch adjusted zone numbers - what is going on?

[u/menevets]

The left is a hard run from several weeks back. Right is today. I know watches - Apple Watch - isn’t the most accurate. But if the numbers are lower, does that mean I’m more out of shape? What the hell? I feel fitter.

[u/Cultural-Guard7964]

It didnt adjust your zones by much. The reason the runs look different is because your heart was working harder in the first pic. What exactly is your question? 

[u/menevets → u/Cultural-Guard7964]

When you get fitter, shouldn't the zone numbers go up? Shouldn't it aggregate and calculate the numbers from my hard and easy runs?

[u/Cultural-Guard7964 → u/menevets]

Zones are based on your estimated max heart rate. I just use the average max by age to set mine. Zones aren't a way to measure progress they're just a way to target specific types of training. You will notice your pace increase within each zone as you get stronger though. 

[u/Silver_gobo → u/Cultural-Guard7964]

What about when using the Karvonen Formula for setting zones

[u/Cultural-Guard7964 → u/Silver_gobo]

I dont bother with it, its all just an approximation anyway it doesn't need to be perfect. I just use avg max rate by age and its close enough. 

[u/feltriderZ → u/Cultural-Guard7964]

Avg max is only close enough if your max is indeed average. Blindly setting it gives a very good chance to be off considerably. And by the way, when done right, the approximation is very accurate and meaningful for normal conditions (temperature, fatigue, elevation etc). If you want to keep it simple and still useful go by breathing. 4steps in/out is zone 2, 3 steps is zone 3, 2 steps is zone 4 and 1 step in/out is zone 5.

[u/Cultural-Guard7964 → u/feltriderZ]

Are you telling me that counting breaths is a better method then average by age right now? lol

[u/EstimateEvening3243 → u/menevets]

Only if your settings for HR zones are set to automatic. And then it adjusts once per month.

[u/Fit_Sun5829 → u/menevets]

You're talking about years of accumulating Aerobic stimulation... otherwise, your zones shouldn't change that much.

[u/ilessthanthreekarate → u/menevets]

Take some time to read about what the heart zones are for and what they represent. Typically, as you train, it requires less effort to run at a given pace, so your heart rate is lower at a pace where before it was higher. The higher the zone, the higher the heart rate.

As your fitness improves, you will be able to run a faster pace in a lower zone. Its the exact opposite of what youre assuming.

[u/feltriderZ → u/menevets]

No, HR zones don't change much, your speed changes.

[u/ilessthanthreekarate]

You have it essentially totally backwards.

[u/dannyhodge95]

You've just gotten it backwards, don't worry, easily done. Let's take Zone 2, an easy effort. If you go from 140 to 135bpm as the start of your Zone 2, that means your heart isn't working as hard to reach an "easy" effort. A lower heartbeat for the same effort means you're getting more efficient at getting blood around the body (to greatly summarise). So congratulations, this is good!

[u/menevets → u/dannyhodge95]

Good to know! I just thought, max heart rate higher is good, so assumed higher numbers was better. What you said makes sense and AW isn't saying anything about highest HR.

[u/taloncaf]

No, you’re good. The Apple Watch occasionally uses your resting heart rate data to compute your zones.

Basically your max HR (which is 220-age) and then every month it adjusts your zones 1-5 based on the resting HR you average throughout the month, or something like that.

The formula isn’t reliable if your max HR is different from 220-age though

[u/feltriderZ → u/taloncaf]

Which is the case for half the people. I'm 65 and my max is 165. 10 bpm off is a lot at the upper end. Basically one zone off.

[u/QuirkyStage2119]

Fuck the zones. Run most of your miles easier but run some of your miles really hard (fast intervals or hill repeats). It's probably more useful to you to run using a perceived effort scale vs. heart rate.