One word: Sleep.
Studies have shown that sleep is one of the most important processes in our lives. It is essential for learning, recovery, and information processing – whether it’s preparing for tomorrow’s work presentation, or recovering from the day’s workout, there is nothing more important than proper rest.
Studies have shown that improved sleep correlates with better performance at high intensities. One paper, authored by Cheri Mah, a researcher at Stanford, showed that increased sleep improved sprint times of basketball players by 5%. In the context of elite sports, 5% is much more than a marginal gain.