IMO, it isn't as much about the activity, it is how the activity is performed. Deer learn to pattern us better than we pattern them. If you drove the same road every day and used a road feeder, the deer would get accustomed to your movements and can be trained to come to the sound rather than run away. If you are rarely on the property and go through on a 4 wheeler, you are going to change the activity in the woods and can push alot of deer.

Same theory is used on some shooting ranges. Deer have been seen down range while shooting is going on. The deer become conditioned to the noises that are in their environment and our movement in their home.

When hunting, pressure becomes too much IMO when people make mistakes. Entry and exit points. Time of arrival and departure. Routes used to access the stand locations. Wind direction. Etc. You can only push the mature deer so many times before they will avoid certain areas.

Doe are notorious for checking stand locations, especially of a bow hunter. They will circle down wind and I have seen them walk right up and look to see if you are in it.

Typically, I let the deer tell me what is "too much" but sometimes you never even realize the effects you are having.

Good luck