The relentless compressing force of gravity wrecks havoc on your muscles, joints, and tendons. The removal of that force alone provides a near miraculous opportunity for rapid physical rejuvenation. When combined with the synergistic effects of increased blood flow and circulation to the extremities, you are provided with an unparalleled physical advantage.
Many of us can also suffer from overuse issues both physical and central nervous system; time in a float tank will reduce a lot of the associated adrenal strain.