People often ask me for tips on running, and living a healthy life.

One of my favourites is real easy: drink more water. It’s amazing how many problems a glass of water can solve. Feeling tired in the afternoon? Drink a glass of water. Can’t sleep at night? Drink a glass of water. Got a headache or stomach-ache? Here – try some water.

I’m not alone in believing this. The First Lady of the United States, Michelle Obama, (who appears as a minor character in my novel, by the way) recently gave a shout-out to the greatest drink of all: