My first ultra marathon was a 50K (31 miles). It was also my first trail run. It’s my belief that most of us will never know what our bodies are capable of physically. Until we truly test ourselves, it is difficult to wrap our hands around the tremendous amount of stress our bodies can sustain.
I like to test things out, often before I am fully commit to something. On my first trail run I was neither brave enough nor skilled enough to tackle it with bare feet. The rocks, roots, sticks and thorns would have inevitably damaged my pampered feet. So instead I ran it in barefoot shoes called Vibram Five Fingers.
There is no support to these rubber foot gloves. When your feet become strong enough, support is no longer necessary. The shoes play a similar role to the protection we gain from developing a callus, only the rubber blocks important sensory receptors at the skin level that force us to run light atop debris that could break the skin. These proprioceptors keep us injury free and allow us to manage hundreds of miles on rocks, debris and extreme terrain while barefoot or in thin sandals.
In traditional running shoes I would not have noticed that fatigue was inhibiting me from using the leg muscles to absorb the impact of each stride. After muscle fatigue set in, I started landing with the knee extended or locked out due to the biomechanics of the heel-to-toe striking pattern. The micro trauma over 31 miles of trail running, using the architecture of the joint verses muscles of the leg to stabilize, would have left my back and knees sore for weeks. Instead, by using the proper mechanics of the foot, the muscles in my feet were only sore for a day or two.
Cory Torkelson, CSCS
Barefoot Runner