Did a hard 12-miler over the weekend and noticed quite a bit of soreness in my lower abs and hip flexors afterwards. If I run hard, its not uncommon for me to have sore calves and quads, but I’ve never had sore abs from a run before.
Actually, right now. I did a 2 hour steep, rocky trail run yesterday and I can feel it in my abs today. I assume its from the balance required to not topple over on the down hill portions.
I’d speculate that you had to utilize a higher knee lift on the steep uphills, calling on more effort from your lower abs and hip flexors. Knee lifts and flutter kicks might be called for.
I am experiencing this right now. Did the Flying Pig half yesterday which was very hilly for me (I live in super flat Chicago) and my hip flexors and stomach are very soar today. I thought it might have been just because I pushed myself harder yesterday and threw myself down the downhills but maybe it was all the uphills that are hurting me today.