Each hour of the day is ruled by a specific organ and afternoon fatigue may be about how much water you drink today and yesterday.
The hours of 3-7p are ruled by the Element of Water. The Bladder and the Kidney Meridians.
If you have been not drinking enough water, dehydrated, or just partied too much last night your Kidney Meridian will measure very high and your Bladder Meridian will be very low. With two meridians that are next to each other in the middle of the day and the energy level must go from very low to very high…you might as well go and run 5 miles because you are almost exuding the same amount of energy to maintain such an imbalance.
Coffee and sugar and usually “helpers” here however, they may help you for the next hour but since they are even more dehydrating your evening will become even more exhausting.