Hi, Elena here, walker, lifter, watch skeptic

The watch VO2max is basically a math guess form pace and HR. Mine moved 3 points when I changed wrist position lol. Do you use a chest strap?

Chest strap made my zone 2 HR way less jumpy. Wrist was reading cadence on intervals.

Ferritin 41 is not low-low, but for endurance folks some feel better higher. Did you test before starting?

I was at 41 ferritin too and my resting HR plateaued. Not saying supplement, just that iron status can matter.

I'd be careful blaming ferritin alone. My ferritin was 38 and I still added 4 points over 12 weeks by increasing easy volume from 3 to 5 hours. The watch estimate lagged 3 weeks behind actual 5k improvement. What's your weekly easy time? If it's under 4 hours, that's the first thing I'd look at, not labs. Also, my sleep was already decent, so volume was the lever. I did no intensity for the first month, just easy. It felt stupid slow at first, but HR at a fixed pace dropped 12 bpm.

Agree the watch lags. Mine said 41 for two months, then jumped to 45 after a random trail run.

What did your 5k or Cooper test actually do? That's the real question. VO2max estimates are entertainment until you anchor them.

Following. Same flatline, but my RHR kept dropping.

My labs looekd similar. Adding a lactate test showed my easy was too hard. That was the missing data.

Easy too hard is the classic. My zone 2 was actually zone 3 for a year because I used 220-age.

220-age si trash for me too. Talk test fixed it.

Not to derail, but the ferritin thread is interesting. I had ferritin 35, started eating more red meat and vitamin C with meals, and my HRV rose 8 ms in 6 weeks. No supplement. Could be coincidence with better sleep. If you already sleep 7h, I'd still focus on volume first. Also, did you take the watch off for a week to see if the number just resets? Mine did.

Try a 20 min threshold test and compare HR at pace. If that improved but VO2max didn't, ignore the watch.