Can ketone esters help fuel elite riders to victory? Is this new legal food supplement the next big advance in sports nutrition? This documentary delves deep into the theory and research surrounding the mystery of the newest super supplement, ketone esters, to find out if they do improve performance. Something at the sharp end of modern nutrition technology comes at a hefty price. Are they worth it though? And why do the majority of world tour teams just want to talk about something else? Endurance cyclist and scientist Jonathan Shubert investigates.