In general, hitting the wall refers to depleting your stored glycogen and the feelings of fatigue and negativity that typically accompany it. - RunnersWorld.com

Yesterday I experienced this for the first time. Boy is it sudden, dramatic, and confusing. Everything is fine, half-way through a 12 mile run, then BAM. “You shall run no further good sir”.

To make matters worse I had to walk back (6 miles) in the cold, drenched in sweat, with my tail between my legs, questioning my manhood.

It was a miserable experience. One that I don’t want to have again. But also one that I am glad to have had.