You know a theory is janky when even its Wikipedia page has “(pseudoscience)” in its title. That’s the case with so-called “biorhythms,” or periods of 23, 28, and 33 days that supposedly predict how ...

Students who perform poorly in class now have another excuse: Their schedules may be out of sync from their body biorhythms. New research shows that body clocks have a big bearing on student ...

Last time, I discussed, in a very superficial way, the concept of circadian rhythms, such as being hungry or sleepy at different times of the day. And I mentioned how these genuine circadian rhythms ...

The average length of a movie is 90 minutes. And that doesn't seem to be an accident. If you ask the experts on these things, they'll tell you that many of the functions of your body and brain are set ...

Who remembers biorhythms? I do. I was about nine when biorhythm was all the rage, peaking in the mid to late 1970s in North America. Conterminous to a society which sported mood rings, cowl necks, ...

Lindsey Ellefson is Lifehacker’s Features Editor. She currently covers study and productivity hacks, as well as household and digital decluttering, and oversees the freelancers on the sex and ...