Now that it is finally summer and warmer outside, more runners take to the streets!
It is very rare that running surfaces are perfectly level. There is always some degree of tilt (sidewalks and the sides of roads, for instance). Running constantly on a tilted road surface can promote more ankle, knee, hip and pelvic injuries. These will create imbalances in the body as it is trying to regulate and control the running surface.
Over the course of many kilometers per week, month, year(s), this can add an unecessary toll on the body.
In order to get the benefit of running and avoiding injuries, we suggest coming back on the same side of the road. More often than not, runners will always run against traffic for safety purposes. However, if this is constant throughout the duration of the run, then the "inside" leg is always a bit lower than the "outside" leg! (Roads are designed with a slight tilt so rain water can make its way into the sewer systems).
Conversely, if you were on a cambered track, the same would apply : for every turn you do clockwise, do the same counter-clockwise!