Leaders who appear physically fit are viewed as better leaders. According to an article on weeklyleader.net:
“Fitness does so much more than just keep the extra weight off and prevent us from blaming the cleaners for shrinking our clothes. It increases mental stamina and endurance as well. It helps one weather stressful events with aplomb, and to keep one's head when all around them are losing theirs. The leader of the group, the one expected to make a good decision under stress and chart an effective course, should take advantage of the extra mental acuity and sharpness that comes with being physically fit.”
One study from the Centre for Creative Leadership found that individuals who exercise are significantly more effective leaders than those who don’t. According to the study, executives who exercise rate significantly higher on skills such as leading others (inter-personal savvy, inspiring commitment, and creating synergy), leading by personal example and results orientation than non-exercisers.
Probably one of the simplest and easiest exercises to do is to take a walk. According to the Franklin Institute, walking is very beneficial to the brain because it “increases blood circulation and the oxygen and glucose that reach your brain.” As you walk, you effectively oxygenate your brain. Maybe this is why walking can “clear your head” and help you to think better.