The nervous system will immediately attempt to dissipate that energy by sending it back out of the spinal chord. If these impulses then fire along facilitated pathways into the muscular system, they could cause muscle tightness and soreness.
If they fire into the blood vessels, restricted circulation often results. When these impulses fire into the skin, you may experience abnormal thermal sensations (i.e. feeling hot or cold, prickling, itching etc).
These will be felt more by many people as cellular transformation occurs in the body. It is like your engines are being rebuilt and the temperature gauge is being replaced.