Naps and Cognitive Performance: Length, Timing and the Evidence
A short nap reliably lifts alertness; a longer one can leave you groggy first. What the nap studies tested, the coffee nap, and the health questions.
Caffeine and Cognitive Performance: What It Really Does
Caffeine reliably sharpens alertness and attention, not memory or reasoning. What the trials show on dose, sleep timing, tolerance and safety.
