Peer-reviewed research concerning caffeine, summarized and appraised in plain language with every source cited.
This study tested how different doses and timing of caffeine affect sleep in men who usually drink moderate amounts. It compared a placebo, 100 mg, and 400 mg of caffeine…
This study set out to measure how the amount of caffeine in the blood tracks with sleep depth and heart activity. Twenty-one healthy young men took either 160 mg of…
This study set out to see whether a regular daytime coffee habit disturbs sleep in young men who already drink it. Twenty men went through three 10 day conditions, daily…