It's old news that sleep is one of the most important factors for strength and building muscle. Your body needs at least 7-8 hours of sleep a day for optimal function.
Bodybuilding is all about building muscle, definition, fat-loss, and being in shape all-around. Sleep plays a vital role in either building new skeletal muscle, recovering, and fat-loss.
If you are experiencing a lack of sleep, your body will feel weak and tired all day. You can, of course, drink a cup of coffee or pre-workout, but the lack of sleep will catch up on you later on.
Some bodybuilders also experience insomnia from some compounds they have to take to get in shape. A natural sleep aid can help to get relaxed and improve REM sleep.