Advanced Sleep Phase, or ASP, is a sleep pattern that deals with someone going to bed before 8 p.m. and waking up completely rested around 4 or 5 a.m. It is considered to be incredibly rare in today’s times, but a new study of 2,422 people attending sleep clinics in the US has suggested that more may be practicing ASP than previously thought. ASP leads to a shift in the body's circadian rhythm, meaning the sleep-inducing hormone melatonin is produced by the brain much earlier in the evening. A drop in body temperature occurs with that production as well. The study found that eight of the 2,422 participants displayed ASP (around 0.33 percent) – far more than experts expected. Learn more here.