Hi, I'm just starting to get back into the gym after a few years of basically being a lazy ass. So I'm weak as hell & have to start at the begining with these light ass weights that I feel embarrased to lift because I'm actually getting a workout & straining & all. Anyway, I've been experiencing some wierd shakes while doing certain exercises. when doing crunches, lat pull downs, & some other things. How long before this goes away?