4. Bird Dog
This exercise entirely relies on the perfect posture. The best you focus and maintain the posture the best is for your body. Counts or difficulty are not what will help, so focus on the body form. Make yourself stay in a crawling position, and lift one of your hands and the opposite leg. Do 10 reps on each side per day. This helps stabilize and maximize back muscles, especially for those who are always fixed with a computer or a laptop.