Taking my previous post Let it be… on a bit I want to continue the observations.
Running at my comfortable pace the ‘natural’ pace my foot follows a traditional heel to toe rocking motion.
Running at my HMPace my foot follows a shorter heel to toe rocking motion beginning slightly forward of my heel.
At ‘flat out’ or interval pace I am running on my toes. All my weight is concentrated on the mid to front of my foot. (This is not an issue as you will understand shortly)
Focusing primarily on the natural pace work for a moment. If I run at the natural form I land on my heel, my foot pronates inwards with slight over pronation on the left leg (controlled by my choice of shoe) and through to the mid and forefoot for the propulsion phase of my stride.
What happens if I increase the cadence at the same pace?
Well, first of all I have to shorten my stride right down to fit that many steps into the time. Lets reverse the maths for a second…..
By the magic of paper and pencil, running at my HMPace cadence (180bpm) at natural speed I would have a stride length of 1.06 meters and my ground contact time remaining the same 0.666 seconds per side per minute the following happens –
- 1000m (distance covered) / 1.15m (stride length) x 0.712 (GC Time) = 619.13 seconds total GC time / km
- 1000m (distance covered) / 1.06m (stride length) x 0.666 (GC Time) = 628.3 seconds total GC time / km
Do you see what has happened?
Following conventional wisdom by shortening my stride and increasing my cadence results in me incurring LONGER ground contact time and all while I am more loaded onto the front of my foot. So in effect spreading more body mass over a smaller area more often per kilometer!!
What I am identifying in a long and convoluted manner is that forefoot running is not the be all and end all of running. In certain circumstances it can be a nice idea to aspire to achieving but actually be detrimental to your overall running health.
There are mitigating factors and I’ll examine those next so that it is not all about sensationalising the topic.