Saturday, May 5, 2012

Barefoot on Tarmac - Pirie vs ChiRunning

Barefoot on Tarmac
Started my run today properly barefoot for the first 3k. The idea was to start to toughen up the skin so that this distance can be extended over the summer. The tarmac is however incredibly abrasive. It's like running on sandpaper. Quite annoyingly I was already feeling blisters after 2k on the right foot - same place as usual - the big toe and the under the second metatarsal joint. I know that this is telling me that I'm probably pushing off with the right foot - but it's so subtle that I can barely feel it. I can however really feel the blister growing. At around 3k I stopped at a park bench and put on the VFF bikilas. It's true that everything in life is relative - they felt amazingly comfortable and like super padded springy shoes despite being the most minimalist shoes on the market. Despite gravel chips and bits of trees all over the tarmac I didn't once experience any discomfort other than the abrasion. The midfoot to forefoot strike absorbs everything. 

Today I was surprised to still not have recovered my energy levels after two consecutive hard days on the bike during the week. It was a good day then to work on form and technique. The idea of starting the run barefoot is to prioritise "feeling" and to make adjustments due to clear feedback from the feet. Once the feet need to be covered then for the rest of the run there is still some resonance of the feedback to work on - especially thanks to the new set of blisters! 

I wanted to experiment between Gordon Pirie's "springing" by using the arms strongly and ChiRunning's leaning forward and lifting the feet higher behind - to see how each affected both stride length and speed. ChiRunning technique was appealing because it eased the pressure on the blisters by minimising any pushing off with the feet. In ChiRunning you are supposed to use the lower abdomen to support your posture instead of your lower back. This becomes more pronounced as you tilt more forwards from the ankles. What is interesting to feel is that the vertical crunch of the lower abdomen needed for postural control then blends into the lower abdominal action for supporting the forward tilt. It's a nice confirmation that the mechanics make good sense. When I became tired I tried to tilt more forwards and keep the feet from advancing in front - focusing on lifting them high behind. I found that could sustain a speed near 27 km/hr without much trouble over a short distance at the end of the session. It's a nice feeling of supporting posture and tilt with the abdominals in front of the body and the feet extending high and behind. It's completely counter-intuitive for me because I would have done the opposite in the past. There's no way I'd have found this sensation without learning it. I found that Pirie's arm motion was correct in that the intensity needs to be proportional to the work being done by the legs. If you get lazy with the arms then you lose it down below too. I got into a nice rhythm with the arms and slight twist of the spine during the counter rotation of the body. I looked for the sensation of connection so that the hands felt like they had weights in them all the time. Going uphill I tried ChiRunning's idea of pushing upwards with the hands - right up to face height. It works!  

Avoiding the push-off and lifting the heels higher - but not letting the knees come high or ahead - causes a low stance with the knees slightly flexed - exactly as Pirie describes himself. It's like the spring comes automatically even without pushing off. Acceleration is not a problem even without trying to "spring" or push-off. Pirie points out that stride is lengthened by travelling further in the air between foot contacts. It seems that this can be achieved simply by lifting the feet higher and getting more speed from gravity - rather than exaggerating the spring.

In conclusion I found that Pirie's ideas seem to compliment ChiRunning but it's the ChiRunning stuff that is more insightful and fundamental.

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