That bottle you're reusing over and over has been compared to a toilet seat.

We're constantly being told to drink more and more water, as the recommended daily allowance is reportedly 2.5L. Instead of spending a small fortune on buying bottled water, it's much easier to just refill a bottle you bought a couple of days ago to save yourself a few bob. However, it's been discovered that your seemingly clean water bottle is actually very dirty. According to treadmillreviews, the bottle you're using to get water is covered in germs. Based on a study of 12 bottles, it was found that reusable drinking containers are crawling with a huge number of cells of bacteria: more than 300,000 units per square cm (CFU/sq cm). In comparison to a dog's or cat's toy, which only holds 47,000 bacteria cells, it's worrying to think our water bottles are that dirty. What's worrying is that the bacteria that is tested for isn't visible to the human eye so we don't even know we're putting it in our mouths. The germs in water bottles formulate because many people don't wash their bottles properly and that combined with sweat and all the daily germs we come into contact with on a daily basis means there's tonnes of bacteria in every bottle we reuse. Of all the gym bottles that were tested, water bottles with a straw top was found to be the least harmful, only holding 25.4 units of bacteria per sq/cm. Researchers conducting the study recommended buying stainless steel bottles, which hold much less bacteria or buying a reusable gym bottle and putting it in the dishwasher everyday so it is properly cleaned.