Challenging the brain by exposing it to new situations, tasks and skills can improve its efficiency, much like strength training does for our muscles. But maximum efficiency requires optimal rest.

It might come as a surprise to learn that the brain responds to training in much the same way as our muscles, even though most of us never think about it that way. Clear thinking, focus, creativity and good judgment are built through challenge, when the brain is asked to stretch beyond routine rather than run on autopilot. That slight mental discomfort is often the sign that the brain is actually being trained, a lot like that good workout burn in your muscles.