What movements differ between the appearance of running casual and running fast?

Question

This sounds like a very specific question, but Im only interested in the reason for the general or common impressions I hear on my running form. What I hear much of the time is that I appear to be running in a very casual way or that Im not showing alot of effort. Ive heard this many times from people and even once while running in the snow. Actually once I flipped off a NCO for saying this in the military during sprints because I was actually running my hardest. Recently I heard this during a marathon when I was running at a medium-hard effort. Im surprised because I recently started an effort to run faster, and so I shouldnt appear the same any more because Im not taking it easy as before.

Im interested in my running form and would like to know: What movements differ between the appearance of running casual and running fast?

After all, every still picture of Usain Bolt appears fast.

Answer 1

Without seeing you running, it's very difficult to determine much about your running form. I assume that you're keeping up speed with your peers, right?

However, perhaps it's possible to guess away at this if we can get feedback from you. My first bet is that it's a matter of how upright you are. For whatever reason, it makes a large difference in the visual cue as to whether someone is actually running. Take the following image:

The runner on the left has a much more upright posture, arms close to her side, while the runner on the right has their torso oriented more forward, with arms pumping. Frankly, the amount of tilt forward is more a personal choice than anything else, since a lot of your power is coming from your legs and you may very well be bounding forward at a good speed, but it might be what others are cuing off of.