Just watched the first minute or so of that video. I'm 72 and have no doubt that if I tried that first shoulder stretching exercise, I could kiss my trad shooting days goodbye. I do warm up before shooting, most days anyway, by simply drawing my bow a little farther from brace gradually from zero to full draw in small increments with some downtime in between each longer pull. As far as hunting situations are concerned, I will draw the bow occasionally after ascertaining, as best I can, that there are no critters nearby to catch the movement. So far, so good. Pulled muscles ain't no fun.