Yes on foot strike change – my previous study found that a lot of mid-forefoot strikers revert to heel later in a marathon (I compared them at 10K and 32K). And there is some evidence that mid-forefoot increases in frequency in faster runners, but I did not find that pattern in my own marathon study.

Any major change to your training should be made gradually and progressively. Running barefoot or in a minimalist shoe stresses the body in a very different way that running in a traditional shoe, and to rapid a transition can lead to injury. Rotating between a minimal shoe and a classic shoe and building mileage very slowly in the minimal shoe is one approach.

Do you think that is possible running with minimalist running shoes and classic alternatively to avoid this big problem or should i reduce the distance and runs/week?