It feels good to stretch your body out in the morning, but avoid anything too aggressive. Health and wellness coach Jeffrey Siegel says that the spinal discs naturally absorb fluid as your body restores its hydration balance during sleep. He cautions that while the discs expand, sometimes making you a bit taller in the morning, this natural process also limits movement of the vertebrae and causes the spine to stiffen. As a result, flexing and bending too deeply when you first wake up is not only harder, but potentially dangerous. Move gently right when you wake up to avoid any injuries.