Dont quote me on this but i believe its because there is less circulation to your back/ lower sides and when you workout blood is pumped to your entire body but less to these areas.....but i may be making that up...maybe ill google it.
Dont quote me on this but i believe its because there is less circulation to your back/ lower sides and when you workout blood is pumped to your entire body but less to these areas.....but i may be making that up...maybe ill google it.