Even at my peak of training for a 50 mile ultra marathon last year my posture was kind of crappy by conventional measures. That being said, I can run 50 miles without stopping just fine and I have never sustained a serious injury during my 15+ years as a runner.

Those are completely different muscles, so it makes sense that your posture isn’t different.

Regular Sunday 10 miles here, then I had the pleasure to experience plantar fasciitis. I love running, but the injuries can be really annoying