My watch (945) beeps at the start of most runs, and some rides, telling my training status, sleep the night before, and the what first couple of minutes of the workout are like. I think its on a scale from -10 to +10, although maybe narrower. I think the worst i've gotten is a minus 6 and I definitely dialled it back for that run.

Edit to add:

I just scrolled the Garmin App on my phone and looked at some of the other metrics which rarely look at, and it says my body battery is at 5 out of 100. Do you think if i show my wife that i will get out of helping her in the garden?