Back In Business Perhaps?

Feeling guilty that I skipped out on my long run yesterday, I went to the work gym during my lunch break and cranked out a painful 6 miles. I felt pretty good until mile 4, then had to walk for half a mile due to horrible side cramps. I'm not sure what I'm doing wrong with my breathing to induce these cramps but I imagine I need to strengthen my core more. I felt tired but not too terrible after my run so it looks like I might be back in business for training! Next up: 3 one mile intervals on Wed.