the best strain and the one that you will feel staight away and that will make you ache is to lie supine on the bed , hang the weights, over the side of the bed off the floor ant put yur feet on the bed,i.e. you have your knees bent up. Now added to this by sonmeone else ot Thunders is this: Put your hands on both knees and try to pull up. Also aim knees at oposite end of room walls (like a frog) . Feel that? Oh yeah !