Hi mimc,
My answer is both “yes“ and “no“...
When I have some physical work to do, I do take an extra Mestinon.
For example a couple of years ago, I was taking 2 x 60 mg per day when we took a week tour in Sicily in June. We had warm weather and we did much sightseeing, walking, stair climbing, standing in the sun to listen to the guides etc... and a 3rd Mestinon did the job!
I try to swim every day (250 to 450 meters dependind on my mood and on the weather!) but I wouldn´t increase my dose to swim longer...
Also, Pred could cause in the long run muscle atrophy and I think it is advisable for those who are on Pred (my case) to regularly exercise to avoid that situation, but again one should not overdo it, specially on a continuous basis.
Maurice.