Is it possible to change heart rate goal from daily suggestions?

It should change over time ( but maybe not much) It' will rather propose longer runs i think. It's Important however to have a correct Max Heartrate ( as all of this suggestion's targets are based on that ) and good to have as well is a chest strap to measure your Lactate threshold ( I think it uses this LT values if available as well). 

I tried manual input on max hr but it did not work. Do I have to turn off auto detect max hr?

"For me, I have 'auto-on' enabled because it detects my correct maximum heart rate automatically, so I don't need to enter it manually. However, I'm not sure what didn't work for you. Are you saying that you entered a different value, but the suggestions didn't change? Perhaps you could try going for a run to trigger the re-generation of suggestions. They typically refresh once at midnight and occasionally after an activity. Forcing an activity might prompt the update."

Behind the scenes, the targets for daily suggestions are all based on a % of VO2 Max. This in turn is translated in HR or Pace targets based on the modeled linear and non-linear relationship between VO2, HR and Pace that the watch calculates and maintains over time.

The primary suspect when the targets are off is the HR Max because it is the only user controlled input, aside from completing qualifying runs with good HR and pace data.

Unfortunately, the HR Max auto-detection is not perfect and can easily record the wrong HR Max (whether you use the wrist HR or a chest strap). I recommend to disable the auto-detection and, if your doctor lets you, run a field HR Max test. These are very, very hard tests designed to push you to your limits. The peak HR from these tests is very close your actual HR Max.

There are ways to check your HR Max that are less challenging but less accurate. You could run a 5K as fast as you can and your HR Max should be 4-6bpm higher than your peak HR. You can also run a lactate threshold test with the watch. If you are a week-end athlete, expect your LTHR to be 85% of your HR Max. If you are well trained, it could be 90%.

Regardless, if you change your HR Max it will take a few weeks for the VO2 Max model to adjust and the targets to change accordingly.

Etupes25 said:

You can also run a lactate threshold test with the watch. If you are a week-end athlete, expect your LTHR to be 85% of your HR Max. If you are well trained, it could be 90%.

ha, never thought of it that way ;) that's neat ( also it works for my HRmax, LT relationship )  

Thanks so much for your time, this is really helpful. Will try out your suggestions