I'm struggling with the technique you described in your bench pressing video. I have always been advised by others to bench press with the back arched and the shoulders pulled back, nobody has ever mentioned shrugging the shoulders while benching. Anyway I tried it yesterday and it just feels uncomfortable. It seems as if I'm wasting too much energy just maintaining the shrugged position throughout the lift and I actually feel unstable during the lift. Also I'm not able to move the bar up and down as fast as I normally would and have to therefore use less weight - Am I supposed to only shrug at the top of the lift or throughout the whole lift?