Tell yourself you’re not tired.
Dwelling on how exhausted you are may only make you feel more run down, according to a new study in the Journal of Experimental Psychology. Researchers asked 164 participants how they’d slept the previous night, then hooked them up to a sham machine that purportedly revealed to scientists their REM sleep. People who were told they had above-average REM sleep performed better on cognitive and attention tasks than those who were told their REM sleep was below average, regardless of how they’d actually slept. Find out how to stop yawning, no matter how tired you feel.