Now we’re down to it. The final installment of our 3-part series on the run shoe market. The killer app? Organic Support.

Neutral, Stability and Motion Control, run shoe tech’s onetime Holy Trinity, have also caught the last train for the coast. (Pardon us, Don McLean.)

Frequency of run sessions, not bulk miles, is the metric. Exit the Challenge in time to enter the season a stronger runner.

The Hawaiian Ironman and Challenge Roth are the 2nd and 3rd most anticipated events of the year. On Dec 15 it’s the 100/100 Challenge!

The Vaporfly 4% is the hard-to-get, expensive, much lighter brother of the Zoom Fly. Is this shoe better than the Zoom Fly? Nope.

Why is this shoe fast for me? I can only say that it works, but not for certain why it works.

It’s like the Asics GT2000. But more cushioned, more springy, and much more flexible in the forefoot.

Is Newton Running back on its heels? Or in the starting blocks for another run for the tape?

Saucony built, probably unintentionally, a near-perfect triathlon shoe for neutral runners. Add heel and and tongue loops and you’re there.

So here we go, running our 100 runs in 100 days challenge for the 11th year in a row. Every year it’s our biggest virtual camp.

Our annual 100/100 Run Challenge begins December 15, and our Guppy Challenge kicks off December 1.

Today we share an image gallery of various professional men during the marathon of the 2016 IRONMAN World Championships in Kona, Hawaii.