Ketones a dietary supplement are suspected by some to be a PED in cycling. News to me. The following link is an overview of the current Tour de France Controversy.
Ketones and stamina enhancement. (https://www.velonews.com/events/tour-de-france/stamina-boosting-ketones-spark-tour-de-france-debate/)
Read up on ketones and the keto diet.
Same goal much better fuel source then simple carbs.