Movement is a Fountain of Youth

Movement (across all major planes and directions) is a fountain of youth. Here are just a few elements of a yoga practice that testify...

Forward folds with a rounded spine (spinal flexion)

... stretch the muscles supporting the spine and open up space between each of the discs in the vertebral column. This process of imbibition allows fluid to flow through the created spaces, allowing the discs to essentially drink the surrounding fluid. As the vertebral column does not have direct access to fluid otherwise, movement such as flexion helps to keep the spinal supple, mobile and young. Flexion also compresses the front side of the body, for a moment, limiting space to the abdominal organs to then allow fresh fluid to flow back through.

Backbends (spinal extension) 

...strengthen the muscles supporting the spine and increase spinal flexibility. With the upper thoracic spine elevated and the heart lifted, backbends are also heart openers that encourage deeper energy and emotions— joy, hurt—to rise to the surface and be released.  Backbends, then, may increase strength and flexibility not only physically, but also psychologically. 

Spinal twisting across the transverse plane tightens the waistline. Inversions send breath and blood-flow to the top of the head.  

Movement deepens activity in our respiratory and circulatory systems, pushes more oxygenated fluids through our lymphatic system and in turn, encourages our digestive system. It strengthens fascial tissue and when working with our own body's weight resistance, it increases bone density. 

Moreover, it feels good to feel good. And, a healthy body is fertile ground for a calm, clear mind.