Recently someone posted a question in a Facebook group about their experience bonking during their first marathon.
His question was based around nutrition. Specifically stating this his seemed to have failed him at mile 18, and he was on the search for alternatives to the gels he used.
My first question to him was, "why do you think your nutrition failed you?"
He stated that around mile 18 or 19 he hit the wall.
I suspected other factors were at play here. We continued the discussion. Below, ...