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.    

Skora Fit Review

SKORA FIT (Men's) Review

Being relatively new to running (started in 2009), I noticed that lowering stack height, lowering heel-height, and increasing ground feel added up to injury free running.  I took that to the extreme and ran barefoot, wafer thin sandals, Vibram five fingers, etc.  After dialing in my form, and increasing running economy, I added a little more foot protection to increase my speed and run more confidently on technical trails.  The SKORA FITs are just thick enough to protect my soles from the fist sized rocks scattered on the trails I run.   

My favorite feature is the upper material.  If you focus in on the material, it reminds me of a sweatshirt material with the addition of rubber dots all over.  (Protip: these rubber dots are VERY helpful on rope climbs in a Crossfit WOD). 

The build quality of these shoes is 'top-drawer, the seam between sole and upper appears bulletproof.  

The flexibility of the sole is pretty uniform the mid foot and forefoot give equally.  I always recommend matching the flexible points of a shoe to the hinge points of your foot.  This is easy to do in the FITs.  

They look good in casual dress as well ;).  Wear your flexible shoes around to grow your foot muscles especially if you're transitioning from overly supportive footwear.  

Road and Trails

A growing contingent of minimalistic runners (me included) are not too concerned with 'knobby tread' to have trail-performance.  

I can refer you to millions of years of human trail-running performance that occurred in bare feet, or moccasins.  

For a trail race in the mud, or sheets of ice I will use Katoolas or Yaktraxs.  For a training runs, or exploring, the tread on any SKORA shoes are sufficient if your form is sound.  

So far my FITs only have 200 miles on them, but that includes >40,000 of elevation gain.  The elasticity of the uppers keep my feet from sliding around in the shoes during steep downhills or sharp cornering.  They allow my feet to splay upon foot landing.  There is enough ground-feel to give me the necessary proprioception to shift weight appropriately. 

Summary

Pros

• Durable and sticky soles
• Comfortably elastic uppers 
• High quality materials and construction
• Sufficient ground feel with 'padding' for foot protection

Cons

• Minimalist runners will think the stack height is too high - I will slip on thinner shoes to make sure certain foot muscles don't atrophy 
• I wish the heel-cup fit the heel more snuggly
• Won't make it into my business casual wardrobe I wear at work

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I will keep these shoes in my rotation and I can tell they will last for >1,000miles but they may make my feet lazy.  They are great for Crossfit work outs, road running and trail running.  I would recommend this shoe to 

• Minimalist runners that are ramping up their mileage, add a thicker shoe to their rotation
• More supportive shoe wearers looking to transition to zero-drop/thinner shoes
• Crossfit athletes

For making it through this review.... 20% off by using discount code: skorarunning.com/user/paleorunners

B2R Shoes, yay! (First Look)

I was happy when my former running coach, Eric Orton, said he had a line of shoes coming out.  Eric taught me the importance of cadence, running economy, running-specific leg, core and glute strength (in other words, everything I know).   I am all ears when Eric suggests a shoe, so him 'making' a shoe! Even better!  <<--in summary, I had high expectations.  

The first Born2Run shoe is road shoe available in red or flourescent yellow.  The zero drop (0mm heel to midfoot differential) has become a requirement for running shoes for me.  The shoe is very lightweight at about 7ounces, comparable to Merrells or the latest Vibrams.  When I saw the stack height I feared there would be little ground feel.  The split toe, or cloven sole, seemed novel.  I have Vibram five fingers and Zem Gears so I'm no stranger to having things between my toes.  

I chose a true to size for me.  Sizing is a little bit of a science to me.  It's not about where your toe lands in the front of the shoe, it's about lining up the flexible part of the shoe with the flexible part of your foot <see pic>.  My toes' bend lines up with the natural bend in the shoe (as measured from the heel) perfectly.  <In summary the distance from your heel to your toes' hinge point should match the hinge point of the shoe>.  Fortunately, in this case, this shoe is flexible enough that if you're off a bit it won't matter.  

Putting the shoe on I first noticed how thin the material between my toe was!  It was unnoticeable.  As is explained repeatedly on mobilitywod.com, the gap between my big toe and the rest of my toes gets bigger as my feet get stronger - the cloven shoe helps with that.  Some people with weaknesses or tightly crammed toes may not find this as natural a fit as I did.  I then noticed even though the stack height is tall, the material is thin enough that I had great ground feel.  I could tell if I was standing on a quarter.  The shoe comes with two pairs of tabi socks, so i paired them together.  I then tried my injinji toe socks and found them to also be a great fit, unobtrusive even.  

My first day of wearing them, I took them though a crossfit workout that included box jumps, rope climbs, weightlifting, and running with weights.  The shoe performed very well and didn't slip when sweaty. In fact, the upper gripped the rope well!  The shoe also gave good lateral stability and didn't roll across my foot the way Softstar runamocs, or Zem Gears do for such workouts.

So far I have run in them on paved trails, roads, sidewalks and track for 5-9 mile runs.  My feet felt a little tight post-run; I think I'm calling upon more foot muscles with these shoes than I need for my Merrell trail gloves.  Whenever I feel sore, I'll change shoes the next day and swap back and forth.  I haven't needed to do that in my B2Rs.  I've ran with them for 4 days in a row and counting, hill repeats, hard intervals, recovery.  All good!  

Fit, ground feel, flexibility are all A+.  No seams inside to annoy me, achilles tendon guard is low and flexible.  Can not be improved.  My two tiny complaints: 


a.) my laptop cable has once gotten caught in between the toe seam! I took a couple steps and yanked the cord out (thank goodness it was a Mac - magnetic connector!)


b.) this little liner at the bottom worked its way out of the shoe as I ran! <see pic> it was travelling up my heel during my speed workout day.  Funny that i'll blame the shoe, although it's probably my form - my problem!  ;)

I look forward to beating these shoes up some more and talking more about their longevity. 

Below is a quick, unnarrated vid showing the difference in heft and flexibility between the Brooks True Grit and the B2R Road shoe.  Notice the True Grit's split toe is really artificial, just a slice in the tread.