I came across an unexpected challenge in barefoot running: hot asphalt.
On my last run (on an asphalt trail) I developed blisters on the base of my toes. I had to stop running by the second kilometer when it became evident that I was hurting. It surprised me because I had already been running barefoot succesfully (i.e. without blisters or pain) for over almost two months on sidewalks and streets (cement and pavement). However, the explanation lied not in the terrain but the hour (and conditions) of the run.
It was four o’clock in the afternoon on a sunny 30 degree C day when I ran at the park. Mistake. With the first step I took I felt the warm ground, which was not uncomfortable… at least, not yet. By the first kilometer I could feel the hotness of my skin at the base of my toes, sign which I should have taken more seriously since it meant I had already developed blisters. Consequently, I won’t be doing any running till the pain goes away completely.
So I have since then headed over to TheRunningBarefoot for advice and found this and this to guide me. First, it is interesting to note that a not-so-beginner had the same problem as me. Second, and more importantly, the consensus seems to be that for each type of terrain, and type of weather conditions, a learning process is required. That is to say, that when attempting to run on a new surface the approach should be as if from square one; starting short and building gradually. Of course, the better our form the better our process. Personally, I have to watch out for my cadence, keeping the pace above 180 steps per minute.