Had scheduled to go 16 with 10 at marathon pace. Warmed up with 5 miles in 42 minutes. Things were feeling good at marathon pace (7:03) through 5 miles so picked up the pace slightly to 6:58. Just as I was finishing the 6th MP mile, I got a sharp pain in my lower back that quickly shot down to my right hip almost instantly causing me to limp. I quickly shut it down with a brief cool down and some walking. I took some advil post run and it feels a little better but still limping a bit. I will stretch a bunch this weekend and see how it feels on Monday. If I can run next week, I will avoid any faster paced miles.