Home > Newsletters > Need to Know > News you should know Updated 06 March 2015 Action Point 0 Avoid exercising at night as this can stimulate your nervous system and make falling asleep difficult. Rather exercise in the morning or afternoon as this can help deepen your sleep and make sure you fall asleep quicker. More: Need to KnowNews you should know advertisement Read Health24’s Comments Policy Comment on this story 0 comments Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... Other news Medical Could grinding your teeth cause headaches? Medical 7 alternative remedies for ED Medical Marathon running may cause short-term kidney injury Medical 60% of women who get breast cancer gene test don't need it Diet and nutrition 5 foods that are dangerous to eat after the expiry date News Health24 Health Challenge: Week 34 From our sponsors How to care for your vaginal flora Live healthier Hello? » SEE: Interesting facts about hearing loss Earworms: Let it go Is it bad to sleep with earplugs all the time? SEE: Do women hear better than men? The reason why men often appear not to be listening could be because they actually can't hear you. Confident smile? » Acidic drinks can harm your kids' smiles The facts on bleaching your teeth Am I taking good care of my teeth? Why are my teeth stained? We know the rules – brush your teeth twice a day and floss to keep them healthy. But, have you ever wondered what causes those stains that sometimes appear?