I'm convinced that it's just your body trying to catch up all the sleep it didn't get. Of course, lying down for a long time will have side effect on your musc

I'm convinced that it's just your body trying to catch up all the sleep it didn't get. Of course, lying down for a long time will have side effect on your muscles (headaches, groggyness) but I'm sure your body would return to normal sleep patterns after some time.