TV doctor Michael Mosley has revealed a drink that he says can boost performance and endurance.
The weight-loss expert has founded a number of diets including the Very Fast 800 diet and the new 5:2 diet. These diets focus on when you eat as well as what you eat in order to promote fat burning.
In terms of what you eat, Dr Mosely is a proponent of the fruit and veg rich Mediterranean diet which also features lots of olive oil, oily fish and nuts among other things. He has now also pointed out one specific drink - which can also be a food - that he says he swears by.