50 Everyday Mistakes—and How to Fix Them

Setting your alarm for the middle of a REM cycle

Humans sleep in five-stage cycles. Waking up in the middle of a REM stage (when you sleep deepest) leaves you groggy and grumpy—but get up during one of your light-sleep stages, and you’ll rise feeling refreshed and alert. Find your perfect bedtime with a free site such as sleepyti.me, which gives you four optimal bedtimes based on when you need to get up, or a sleep-tracker app such as Sleepbot, which uses motion and sound sensors to wake you from the lightest phase of your cycle. These are the four stages of sleep and the importance of each.