then you think about you know muscle sparing effective ketone so yeah I think you illustrate the point very well mark running on carbohydrates and running on fat affect the engine differently would you do do you know if there like certain populations because you mentioned like 30% of the population probably doesn't run as well on carbohydrates I think 70% of the population but are there certain populations that generally do run better on carbs or we don't know about that yet