Hi Kain, and welcome to COOP or DIE.
You are right, the max health is not saved in the profile, only the current health. So when you restart, your max health is capped to 100, and if your current health is above, it is set to 100 too.
To be right I have never really considered this fact. I think we could consider the adrenaline bonus to be a "per session" bonus. So it is OK to reset it while returning to start map...
Also, like there is an Adrenaline item in the first map, if it was saved, there could be an exploit when players restart the map over and over for increasing their max health.