Starting the day with a glass of water can prevent dehydration rather than cure it later in the day, especially since you've gone without anything to drink for several hours.

Dehydration can cause issues with concentration and fatigue, so sipping some H2O at the start of the day might help you beat that morning's brain fog.

Starting the day with a glass of water also makes it easy to start a water-drinking routine. Establishing a healthy habit gets the ball rolling with your water consumption.

Once that habit is established, The British Journal of General Practice notes that it not only becomes second nature, but you may feel strange not drinking water first.