It's because walls are a bit too steep. If you made them into paraboloid, a per would naturally climb as high as they need to, to be able to run symmetrically.
Person running would need to constantly turn a bit to one side to not climb further up the wall. So it shouldn't be much different from running in circles on flat surface.
Not sure if runners that train by running in small circles are concerned about evenness and try to run the same amount clockwise and counter clockwise to even things out.
Ex collegiate track and XC athlete, yes, we'd alternate directions once in a while when doing long workouts on the track. It's a 36.5m radius, and it does get to you eventually. You feel it in your knees long before your ankles. I ran distance events (1500, 3200, 5k), so I think I had it easier than the 200m and 400m guys (and especially the 400m/300m hurdle guys) whose spikes were desperately clawing at the track to hold the turn, but I did have some workouts with a lot of laps. We didn't bother to make it exactly even, but if we were doing ladder workouts we'd switch directions somewhere near the middle.
Indoor meets often had 200m tracks with tighter (frequently nonstandard!) radii. The good ones were banked, though it never seemed to be at the right angle, always too steep or too shallow.
Every race still goes counterclockwise, though.
Maybe it's my XC side talking, but I'd love to see a track in a figure 8 with an underpass. Left turn, over the bridge, right turn , under the bridge, and repeat! It would break up those monotonous 8 and 12 lap races nicely, and you could fit a longer track in a shorter rectangular building by using the hypotenuse. I'm sure people would hate the hilly incline, though...
I did HS sprinting as cross training for fencing. Fencing is extremely asymmetric, to the point where my right (front) leg could lift twice the weight of my back (left) leg. It was freakish, and probably not healthy lol. It made my sprinting coach really uncomfortable, because my stride looked weird on the straights.
The curves felt great for me though, I really liked the 200m better than the 100m. Can't imagine how shitty it'd have been for a left handed fencer to run track, because the big muscles would be on the inside leg.
That would be extremely interesting, but the fact that you have an incline would change the ideal body type and tactics so much it would be a different sport at that point.
But I would love to see it for medium distances, just to see what crazy stuff would happen!
This is steaming my brain a bit. Is it not the case (assuming an "optimal" tilt of the track) that the inner leg would travel more radii each step, meaning you would travel a larger segment of the circle on every inner step than outer step, ending up with an equal gait? This is my intuition without any formulated proof.
