I’ve been trying to research what I felt was a legitimate and normal question. Do your hip flexors get sore after workouts like other muscles, or is that pain the bad kind of pain. I can’t find anything about soreness. It seems like there is no in-between. Hip flexor pain is the bad pain. I just started up again my regular sprinting training after about a year off. I use it as a supplement for my other workouts, not as a core activity. My hamstrings were sooo sore after the first workout for nearly the entire week, almost more so than my typical hard leg day. It was rough. I felt the soreness immediately after the workout. I didn’t feel the hip flexor pain until I started doing my second workout though – and even just doing the warmup I could feel it. It wasn’t bad enough to prevent me from finishing the workout, but it was a constant low level pain throughout, and getting pretty bad by the end of it. I figured they were just sore, like my hamstrings were. Now I’m not so sure, and am questioning whether I should have pushed through with the workout, making it worse. As a high school track athlete I ran the 400 and 800 and 400 relay and have done many many sprint workouts and this is the first time I have encountered severe soreness in my hip flexors so I’m not sure why it is happening now. *See below for an update two years later.
What I can conclude from reading, is that this is problematic, but quite common, and due to a combination of factors: i.e not long enough warmup, pushing myself too hard for a first workout of sprinting in a long time, improper form, tight hip flexors, relative weakness – I had spent the last three months working on max strength with legs, which did not include any hip flexor work. Things that might have contributed:
1) Tightness in hip flexors. As many of us are sitting most of the day, our hip flexors are in a concentric and tightened position most of the time. Hip flexors are very commonly tight, and need to be regularly stretched out. Here are some good stretches with a diagram showing the muscles: Hip Flexors – Crossfit Reality
2) Weakness in the hip flexors. Strengthening the hip flexors is not typically part of a strength building regimen, but should be. They are an integral part of sprinting, as well as kicks and Olympic Lifts. Here are some good websites for sprinting tips, and working on hip flexor strength and flexibility:
3) I also think the other sports I do contributed to this – e.g. a lot of kicking, which put additional stress on the hip flexors making them susceptible for overuse, more sensitive to being tight, and highlighting the weakness in them. Flexibility is a major issue for me and for my kicks. Maybe sprinting will help loosen them in a way my stretching has not been able to.
Update three months later: This has not happened since. I haven’t changed that much – I make sure I do more of a warmup, and stretch a bit more before the workout, but that’s about it. I’m also not training legs with the same weight I was doing either. Muscle imbalance may have been a factor as well.
Update two years later: I realize now that this was the first warning sign for developing IT Band Syndrome, a knee injury often from running due to improper form and having weak and tight hips. Working on these weaknesses is not an easy fix and takes a lot of focus to counterbalance years of sitting. My above conclusion was wrong, I didn’t fix it after three months, it was just latent. It didn’t matter that I do a lot of sports and am very active. My body became used to using secondary muscles to keep my knee in place while running instead of the hip flexors. This imbalance was highlighted while training for a 50 mile race so I’ve been doing daily rehab exercises for it, and after about a month I can run on my knee again. I will continue to do preventative exercises. More about my struggles with ITBS here.