2 YEAR BUMP LOLZ

And still after all this time i'm struggling to be able to play for a decent amount of time. Is it possible to do some other "exercises" without using a bass that would help build endurace? Basically the muscle (probably several muscles but whatever) that is always causing problems is the one that's relatively round on the outer edge of my left palm. If you make a fist it should protrude a bit. Also it's been referred to as the wack-off muscle if that makes it any clearer lol. It gets worn out quickly, espeically if i'm tapping with my pinky.

And, before you suggest it, no, i'm not going to touch myself all day to get more endurance

Any help is appreciated.