I am pretty sure heavy workouts and even half work outs are not a great idea. You need more gentle exercise like walking (probably boring for you) but still a good exercise.
The idea (I think) is to get some oxygen to the brain like in areobic exersize, but not in a heart pounding kind of way yet.
Check out University of Buffalo -- they are leading the way in trying to resolve concussions with the right amount of exercise.
I am more of an extreme knitter than weight lifter or --whatever.
I am sure more experienced members will weigh in on this.
But it's good you figured out a trigger for you -- that is part of the battle.
Here is a link about U of Buffalo.
http://concussion.buffalo.edu/research.html
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