Tomorrow I’m giving a presentation on “How to choose your perfect running shoe”.
I’ve done these before and while they are similar to the conversation that you have with customers in the shop the setting is different and the crowd is different so you need to be prepared more.
One of the topics that has been batting around in my head for the last while is to do with people overthinking their running.
In my opinion far too many people are getting hung up on heelstriking / forefoot striking etc and as a result are either hanging up their run progress or are injuring themselves.
I briefly touched on this topic before in a post about my selection of shoes and how I use them. In particular how I seem to have preference for different shoes depending on the type of running that is being done. Now, don’t get me wrong I’m not banging a drum about footwear before form, I’m highlighting that they are mutually beneficial areas of your run that should be addressed in training.
As mentioned in that post above, different paces, different shoes suit better or worse.
“What do you mean?”, is the chorus I hear.
Well… let it be…
By this, I am
suggesting recommending that whatever your natural running form is you allow it to flow through. Don’t try and force change on what comes naturally to you, work with it enhance it, make it work for you rather that you trying to work against it.
Take me as an example.
If I go out for a run without any goal, just a nice relaxed run trotting around the area, after a while I settle into a rhythm that just works. I lose myself in the run, relax into the surroundings, find a rhythm that resonates nicely for me. All of this is subconscious and happens when I switch off.
Let me put this in numbers.
I’m 86kg (important to know for later) 6′ tall and using a footpod I know that I run naturally at 83/84 strides per foot per minute with an average stride length of 1:10 – 1:20 meters.
Doing the sums this means –
(83.5 x 2) x 1:15 = 192.05 meters per minute
11.523 km per hour or roughly 5:12 minutes per km is my natural, comfortable pace at which my HR (Heart Rate) will be around 140 bpm (Beats Per Minute).
Now, the important thing to take out of this is that every minute my bodyweight lands on my feet 167 times or to be more precise a multiplier of my body weight creates a landing force on each of my feet 83.5 times per minute which means my Ground Contact time is 0.712 seconds (at this pace) per foot.
Now, I’m not an engineer so I’m not even going to calculate what the point load per square cm is for an 86kg mass landing from approx 25cm is but I’d gladly take someone’s calculations if anyone is good enough to do those for me.
I have a funny intuition that whatever that ^ calculation works out to be it will remain fairly constant through this series of posts.
So what happens if I run faster?
Let’s look at my Half Marathon pace (HMPace) of 4:30 minutes per km.
Again using footpod data 89/92 strides per foot per minute averaging 1:22 – 1:25 meters
(90 x 2) x 1:24 = 223.2 meters per minute
= 13.4 km per hour
The important factor is again Ground Contact time which in this instance is 0.666 seconds.
If I go at a ‘flat-out’ sprint for an interval:
(100 x 2) x 1:60 = 320 meters per minute
=19.2 km per hour or 3:12 minutes per km
Ground Contact time is 0.6 seconds
So the faster I go the less Ground Contact time there is per foot but to achieve this I have to increase the cadence or number of foot landings per minute. Makes sense?
Further examination of this trend in this is that the faster I’m moving, the less ground contact time there is, the higher my cadence, the further forward I am positioned on the foot.
The reason I’m looking at these figures and establishing them is because they have a bearing on the footwear that I should be choosing to suit me naturally but they also have a bearing on what suits you too.
More to follow.