Approximately how long does it take for your liver glycogen stores to be depleted

The depletion of liver glycogen stores will depend on the duration and intensity of the exercise or your body’s movement. Glycogen stores will last 90 minutes if you just have low intensity exercise like distance running but if your body works hard with intense body movement, then the glycogen will be depleted for approximately 20 minutes. Moreover, if you just have the regular routine in your day without any stressful exercise, then the glycogen stores will be depleted in approximately 18 hours.  

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle