Skora's Latest, the Tempos

Spring/Summer Running Season is Coming!

Even though there's Mega-Tons of snow out there, I'm planning ahead.   Although I am 'Mr Minimal Footwear", I am also 'Mr Variety of Footwear.'  In a given week, I will cycle through 2-3 pairs of shoes. This practice:

• Spreads the 'love' of tiny differences in muscle activation that occurs from differing footwear
• Spreads out time that I need to make a (read: another!) shoe investment

In my rotation I will keep higher stack-height shoes.  They are a tool in my shoe-tool-box that I most often pull out when fatigued but need to hit it again, or in a drop bag of an ultra and need extra stack height to go on.  

 Typically, my back to back long runs on a Saturday/Sunday.  The Sunday run I will enter fatigued but I want to hit the larger muscle groups more aggressively.  Therefore, the more supportive shoe comes out!  Saves foot muscle activation when feet are tired. 

The Tempos are now my go to shoe for this purpose.  Holy cow, comfy.  The first two hours I owned them I ran 14miles at a decent clip.  The breathable upper will be heaven-sent in hotter weather, especially hitting the pavement.  On trails, I'll be bombing down a little more aggressively than normal - which will give me a good training benefit there! (22mm stack height, medium EVA cushion).  

Things I really dig: 

• Grooves in sole.  Even though it's a tall shoe for me, grooves make it flexible.  I'm getting good foot mobility in there!
• Breathable upper.  This mesh will be VERY refreshing.  I plan to wear them for my 100 km Road Ultra coming in mid March
• Smart Lug Placement.  Great traction even on pea-gravel, sand collected on road shoulders.  
• Zero drop. This should go without saying for me... We all have these amazing springs that return ground force reactions.  An elevated heel reduces those springs' effectiveness.  Zero-drop is a prerequisite for me (and should be for you.) 
• Subtle little curve in the sole. When I am running long miles on unchanging surfaces (like road running). I find I will consciously adjust toe emphasis.  Force toes to relax, or curve them up, or press them down.  Varies over long runs.  The sole in the Tempos have a subtle upward toe curvature. This *may* weaken toe extensors over time, but my first impression is it feels NICE.  I last longer!  This is another reason why it will work for my road ultra! 
• Color = visibility on the roads.  I'm normally shy, but I want cars, bikes to see me coming!

Things I dig less:

• Can't wear in winter, can't add microspikes.  The elastic from my kahtoolas crush my toes. With thick boiled wool socks they can be a good winter shoe.  But I needs' my spikes'!  
• Will I rely on them too much? Will that weaken foot muscles due to thick(er) cushioning than what I'm used to?  Can't wait to find out :).  

They're really good looking.

I am elastic already i don't need your help

Elasticity - the ability of an object or material to resume its normal shape after being stretched or compressed.

When landing on your foot or feet, you compress tendons, ligaments, muscles.  If you return to original shape quickly enough, the stored energy in the springier elements in this kinetic chain give you an extra push.  Even when running slowly, pop your feet up quickly and deliberately to take advantage of this. 

To test how quick, deliberate motions take less effort, try jumping an imaginary rope at a natural rhythm for 10 jumps.  Then try to jump once every 2 seconds for 10 jumps.  Which took less energy?

 Your natural jump rope rhythm and rate-of-bounce turns on an amazing kinetic chain that returns much of the landing energy (ground force reaction) to the next jump.  To turn off segments of that chain try this.

10 jumps on your imaginary jump rope without bending your knees (turns off quad and hamstring absorption). Reset.  10 jumps on your imaginary rope landing on your heels (turns off lower leg, or gastroc. chain including achilles tendon, calf, soleus, etc). 

Now to the cushioning.  An extreme example of cushioning would be jumping on a trampoline.  If you tried jumping rope on a trampoline, you'd find it's ~3 seconds per hop.  You are adjusting to the resonance of the trampoline's elasticity.   You proved your natural rhythm is much faster, but you had to move to an unnatural rate to accommodate an outside spring put in series with your built-in springs.  

A less dramatic example would be hold a marble 24" from a hard counter top surface and let it bounce.  notice its first bounce is only a few inches less than 24.  Now place a paper towel on that counter and repeat.  You've lost 50% of the bounce.  The marble deforms more and thus returns more energy without the 'help' of the thin cushion.  Try a thicker cushion, try something springy - anything make bounce higher than the original test?  The poor deformed marble needs to re-expand to its original shape to deform this new cushion THEN push itself back up. 

These examples are of simple systems, elasticities that are rigid and only one value.  The beauty of the human form is muscles can tighten and relax in a way to adjust the elastic properties of your kinetic chain.  If you've ever ran across a trampoline, the trick is to pop your foot up so fast that you don't have time to sink into the trampolines large elastic value.  Pop-pop-pop.  That actually takes more energy, but you compensated.  Your shoes' cushions are the same way.  You can compensate, change your natural rate, vary your leg's spring-compliance but why should you? Why are treadmills another layer of springiness you didn't ask for? 

My first minimal shoes were slabs of thin, hard rubber with no foam and no EVA (also... no spring, rockers, air pockets, etc).  It took some getting used to but letting the natural springs take over took me from 5km to 80km runs.  

Beware of those unintended consequences.  Remember that 'help' isn't always helpful.