4. Bird Dog
This exercise completely relies on the perfect posture, the best you focus and maintain the posture the best is for your body. Counts or difficulty are not the things which are going to help, so, focus on the body form. Make yourself stay at a crawling position, lift one of your hand and the opposite leg. Do 10 reps each side per day. This helps to stabilize and maximize back muscles, especially for the ones who are always fixed with a computer or a laptop.