Hi Chetan Mohan. I’m glad you found the post useful and thanks for your comment. Protein shakes per se aren’t necessarily a bad thing if you’re struggling to hit your protein goals, if thats the case then they can be very useful. However, most people are eating more protein than they need to and once they calculate their protein intake they will generally find it easy enough to get it all through food items and not protein shakes. Having said this I have very little experience with marathon running and specific training protocols for marathon running and recovery so would suggest following the advice of your trainer / seeking marathon specific advice. I hope this helps.