I have been training with weights for 25 years, and MY ears started plugging up during/after workouts about 10 years ago and seems to be getting worse. I am 58 yr old female and it used to bother me when I used heavier weights, but lately it doesn't matter. Any ideas? Debbie
The Eustachian tube connects the throat to the middle ear and anything which clogs this or blocks this passage may be the cause in your case.
You can pinch your nose and blow closing your mouth some air, which may open the block or you have to follow up with an ENT.
Take care!