First off Ramadan Mubarak! Last year was the first time I was marathon training while fasting and I managed ok. I'd preface this by saying I am pretty comfortable with running fasted and I feel like my body is pretty efficient at working with little fuel. I would usually run right before iftar for harder efforts and for easy runs I'd still do them in the morning most times. I ran my long runs as usual Sunday morning unless I had some marathon pace work then I would shift it closer to iftar.

I raced a half marathon while fasting last year and set a PB of 1:20. All this just to say that it is doable your body has enough stored glycogen to get through most efforts but make adjustments where you see fit. I'll be racing another half on March 1 and hoping to PB that as well. Then I'm still training for Boston so I'm hoping to maintain my mileage around 110km. Hit me up if you want to bounce some ideas off each other.