Between your demanding boss, a balky computer, and text messages from your child or partner (or both!), by the time 5:30 rolls around you think, Ugh, I am way too tired to run.
Fatigue may seem odd, considering you’ve mostly been parked in a chair for eight hours. But while you may not have physically exerted yourself, you are low on mental energy, and that can make you feel tired, says Daniel Evans, Ph.D., a postdoctoral fellow in the Brown Clinical Psychology Training Program and employed by Butler Hospital in Providence, Rhode Island. When your brain is engaged in making microdecisions all day, it can experience what’s called decision fatigue. The more choices you make, the more drained your brain becomes, which can cause you to abandon good judgment as the hours click by.