India, Aug. 28 -- Think you're doing everything right for your sleep, but still feel exhausted? The reason might be just as simple as sleep regularity. In an August 28 podcast clip shared by Dr Mark Hyman on Instagram, Dr Andy Galpin, PhD, an elite performance coach and scientist, explained why people who sleep 8 hours every day still feel tired when they wake up.

In the clip, Dr Hyman asked Andy to explain the problems most people have with sleep and their causes. According to him, the biggest problem people face with sleep is that they don't pay attention to the outside of total sleep: sleep regularity - going to bed and waking up at the same time each day.

He explained, "They'll say, hey, I got my eight and a half hours or seven and ...