If you're feeling smug by refilling your water bottle several times a day, think again.
While H2O does wonders for the body, re-fillable bottles that aren't washed regularly can be cosy havens for bacteria.
According to a recent study, bacteria levels on water bottles can reach similar numbers to those found in a toilet. But if course, the difference is you aren't putting your mouth near a toilet bowl.
The study, by treadmillreviews, looked at reusable water bottles after each had been used by an athlete for a week.
The bottle with the most bacteria came in at more than 900,000 colony forming units per square centimetre - which is more than the average toilet seat.