Thirsty AF at mile 10

Hello! I’m training for the NYC marathon in November and my long runs just breached the 13 mile mark. I’m finding that at mile 10 I start feeling really, really thirsty and all I want is to chug water.

I always have water with me on my long runs and drink some at every mile. I use Gu gels, eating one every 4 miles. Before my long runs I drink a scoop of Re-Lyte, a coffee, and another glass of water.

I did the Philly marathon last year and experienced the same feeling around mile 10ish but just pushed through (and bonked at mile 22).

Please help me understand what my body needs and how I can fuel it better so I don’t feel the endless thirst in the middle of my long run!