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.
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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.