If you’re conscious, your brain demands your energy and lots of it. Using your brain takes real, honest, physical work — it’s just not visible to us the way using our muscles to exercise is.
Source: Science of US, July 19, 2017.
Because we’re more likely to get sick after period of heightened mental exertion, too, it’s important to treat mental fatigue with the same care we’d grant physical fatigue. If your job (along with your commute) keeps you mostly sedentary, try to break up those large chunks of sitting time with even a little movement, perhaps with multiple trips to the water cooler.
INSIGHTS: The human body reacts to stress similarly, regardless of whether the source is mental, like a difficult math problem, or physical, like running.