I do exercise and it has made a huge difference in keeping a steady sight picture, and being able to shoot better for extended range sessions:
Physical fitness is important.
I have a routine I do to keep muscle mass in my shoulders and forearms, as well as keep my grip strong.
I had a regular exercise regimin that was cycling, pushups/situps, leg lifts - the usual stuff. When I picked up a Glock 34, I got tired after awhile at the range and I got the shakes. I now have a regular exercise regimin designed to strengthen my grip and be able to hold that Glock out there steady. I do running and cycling when I have time but my exercise regimin now is:
Hammer curls:
http://www.exrx.net/WeightExercises/...ammerCurl.html
Ulnar dumbell:
http://www.exrx.net/WeightExercises/...arFlexion.html
Wrist curls:
http://www.exrx.net/WeightExercises/...WristCurl.html
Reverse wrist curls:
http://www.exrx.net/WeightExercises/...WristCurl.html
.