My Garmin Fenix 5s is just about 3 weeks old, and im pretty confident that the Vo2max still hasn't settled to a correct value. Because of this my last week of workouts has been categorized as being unproductive, even if im clearly gaining fitness. I run three times a week, leaving at least a full day of rest in between, which is more than the Fenix 5s recommends me. My stress level according to my watch is pretty low at mid 20's to 30's. My weekly training load is about 700, optimal range. The Fenix 5s explanation is my training load is optimal, but i'm loosing fitness could be because my body might struggle to recover. I don't support this explanation, and i can't find any evidence to support this in the info my Fenix 5s is supplying. I believe my initial predicted vo2max was overshot by as much as 10%, which i believe is a lot, especially considering it hasn't settled after 3 weeks or 9-10 runs. My first run was a 25 minute run, 4,36 km, pace 5:44 min/km, avg. bpm 184. This was pretty much an all out effort posting a predicted vo2max of 45, resulting in a predicted race of about 23:30 min 5k. At this point i knew it was pretty fishy, considering an all out effort 25min. run netted me 4,36km i wouldn't be able to race 5k in 23:30 min. Today three weeks and 9 runs later im running 30 minutes, 5,3km, pace 5:38 min/km, avg. bpm 180 - clearly an improvement. I set three personal bests this week (being 'unproductive') longest run, fastest 1k and fastest 1mile, the last two on my run yesterday - still unproductive. My vo2max has fallen to 43, but its still to high as it predicts a race time of 24:12m 5k - my fastest 5k yet is 27.21. I believe my vo2max should be closer to 40-41, which my apple watch actually got right. I tried changing it manually in my personal settings but i guess that didn't count. I paid four times the amount of money getting this Fenix 5s, and at this point i think my apple watch series 3 did a better job. It's demoralizing spending this amount of money for a watch that is no better at calculation my fitness level, calling me unproductive. How long time will it usually take for a watch like this to get the vo2max right? My apple watch calculated after every run. One run could be vo2max of 40.21 and next run 41.00 and then dropping to 39.85 on my last run if my recovery wasn't long enough. That was a lot more constructive feedback than the Fenix 5s trying to slowly lowering my vo2max calling my effort unproductive until it finally gets it right. Sorry for a bit of a rant here, but im a bit baffled by a watch this caliber getting it roughly 10% wrong, and keep getting it wrong (though slightly less wrong every time) during weeks.
Would it have been better/faster if i slept with my watch? I suspect not, my runs should speak for them selves, and i didn't sleep with the apple watch either.
Edit: Additional info i forgot while ranting...
My first run with this Garmin Fenix 5s watch (25 minute run, 4,36 km, pace 5:44 min/km, avg. bpm 184. as stated previously), had an Aerob TE of 5,0 and Anaerob TE of 3.5 and it recommended 3 days of recovery, so the watch must have know it was a really hard effort, and it still overshot my fitness level by ~10%. I wanted to try an adaptive training program with this watch, however im not confident in the devices ability to creative an adaptive program when it initially overshoots my fitness level by 10% and following weeks struggles to adapt. How will it adapt a training plan to my fitness level, when it can't seem to find my fitness level.