Your key muscles get warmed up and prepped for your workout. It improves your range of motion within your joints, helping to facilitate a full range of motion while working out. They help improve your body awareness. Pay attention while stretching to see if there are any imbalances or "hurts" you want to be aware of before starting your workout. Dynamic stretching helps loosen up your muscles and improve overall flexibility. Warming up the muscles to their working core temperature by stretching them and will therefore improving their function