Yes! There is a whole discussion in our book there are several posts on this forum. See the ADS posts in the Forum Index. See the discussions on Aerobic Threshold/Aerobic Base in the same place.
The main sign is that your can’t do much work/ run fast at low to moderate heart rates. If you have to go very slowly to stay aerobic (being able to carry on a conversation or breath through your nose) you have ADS,