For more than two weeks, I am at 50 - 110 hours of recovery time. Even if one of these days, I was able to complete my first half-marathon.

This is what I would do:

1) Check that you have set the right time when you usually go to sleep and wake up.
2) Check how you wear the watch, specially during sleep. Check when you are still awake, if it seems to pick up the right heart rate.

3) Reboot the watch: I do it daily before charging it during my after workout shower.

My 965 is quite precise about how I sleep: it does not miss to "scold" me because I did not sleep well if I drink too much alcohol, if I go to sleep to late, if I am stressed or if I eat too much too late. It actually helps me a lot to live in a healthier way.

The recovery time is estimated from the Excess Post Exercise Oxygen Consumption, not from sleep data.

EPOC is evaluated during a workout based on your VO2 Max and your resting HR.

Assuming you wear your watch during sleep or during resting periods during the day, the resting HR should be OK.

The VO2 Max evaluation can be off if you HR Max, weight or age information on the watch is off. Most often, the suspect is HR Max.

How did you set your HR Max?

4768577 said:

Among these days, I was able to complete my first half-marathon or near 40 km of bicycle.

Sure. If you train hard and don't use taper periods before races, you can end up racing with high recovery needs. It is not way the best way to do things because of increased risk of stress-induced injury or inflammation and potentially diminished performance.

Note: you might even "feel great" with high recovery needs because of all the stress-induced endorphin in your body. So "listen to your body" mostly applies when your body aches, not when you feel great.

Sleep data affects recovery time. You can start the night with 25 hours RT and you can end with 24 hours (despite 8 hours passed). Then if you do another exercise it could stack up very quickly.

pxl said:

Sleep data affects recovery time

You are correct, some data collected during sleep impacts recovery time, but it is really the stress data that is physiologically relevant here, not the sleep phases classification or the sleep score per se.

"Recently, recovery time has been improved by introducing health and lifestyle tracking data to the analysis for the first time. This means that on compatible Garmin devices, all-day stress tracking and estimated sleep tracking data is now used to increase and decrease your recovery time recommendations, and the impact of your day-to-day activities is now also factored into the equation to complete the picture.

With the improved recovery time calculation, you may now notice that an especially stressful day or a bad night’s sleep will extend the amount of time recommended before your next hard workout. On the other hand, good sleep, low stress and light daily activity levels can all shorten recovery time recommendations."

https://www.garmin.com/en-US/garmin-technology/running-science/physiological-measurements/recovery-time/

Well then, the OP could not wear the watch except during activities, and see if the recovery time problem is still there. If it sill there, the problem would come from bad EPOC estimation. If it goes away, then stress data during the day or night is creating the problem.

I see two possibilities:

1) You really are borderline over-training, and the watch is correct in telling you that you are not properly recovering from your work-outs

2) You are not over-training, and the watch is incorrectly accessing your recovery needs

About (1): As others have pointed out in the thread it is possible to do well, even race with heavy recovery deficit, it might take some weeks or months before the wheels fall off. You are basically just not able to improve properly as the recovery time is when the body can rebuilt and get stronger. There is a high risk of injury.

About (2):

- Check to see if your heart-rate during activities is recorded correctly, if your HR sensor is giving crazy high readings then it will think your easy runs are hard workouts. I always recommend using a heart-rate strap for activities, as wrist-based HR has a much higher error rate.

- Check to see if your Race Prediction times are close to realistic, e.g. what is your half-marathon prediction by the watch compared with your actual half-marathon time? If the watch is severely underestimating your capabilities then that could lead it to think you are going super hard when in-fact you are not working hard.

- Check your maximum HR and also lactate threshold HR are roughly correct, e.g. if the watch thinks your MaxHR is 160 when in realitiy it is 200, then it will think all your workouts are super tough.

- I think that bad sleep measurement shouldn't be the main issue here, it sounds like the recovery time suggested by your activities is already too high, good sleep could only lead to a slightly faster recovery time...