Using Shoe Goo to secure a loose insole in racing flats

I'm a big fan of doing faster workouts in racing flats—lightweight, low-profile running shoes designed for road races.  The light weight allows you to go run faster, and the lower heel-to-toe differential gets your ankles, calves, and Achilles tendon used to working through a broader range of motion.  This can help prevent lower leg injuries and calf soreness that can crop up when you do a longer race in spikes. 

You can see creases from the crumpling

Partially thanks to the now-fading minimalist movement, racing flats have gotten a lot lighter and lower to the ground over the past several years.  While this is great from a performance perspective, the drive for ultra-light shoes sometimes causes design flaws to be overlooked, and this can ruin an otherwise-great shoe. 

I've been wearing New Balance's RC5000 flat in track workouts and road races for about nine months now, and overall, it's been great.  But recently I've had problems with the shoe's insole crumpling up under my toes.  Usually, if a racing flat has an unusually-thin insole, as the RC5000 does, it is glued down so this does not happen.  This is the case with virtually all insoles in spikes as well—having a flap of foam or fabric peel up under your forefoot during a race or workout is extremely irritating.  But New Balance either chose not to glue it down, or used an inferior glue that can't withstand the stresses of fast running. 

In any case, I decided to glue the insole back into the shoe so I could keep using these flats.  I contacted New Balance to see if they had any advice on what adhesive to use, but their response, quoted below, wasn't particularly helpful:

We don't recommend gluing your insoles in your shoes. We make our shoes with removable inserts to allow you to further customize your shoe fit through the use of our upgraded insoles or your own orthotic. You can try another type of insole, such as Dr. Scholl's. Another idea is trying a different lacing method to keep your insoles from moving

So instead, I did some research.  Surprisingly, there is not much on the internet about how to fix a running shoe insole that's peeling or crumpling up under your foot.  I've used Super Glue (cyanoacrylate) to fix a peeling insole before, but that was on a pair of Nike spikes with a flat, smooth surface immediately underneath the insole.  The bottom of the New Balance flat has a mesh overlay, visible above, and I suspected that Super Glue would not adhere very well to it and could potentially leave hard lumps under my feet.  So that wouldn't do.  I considered a number of other adhesives, like contact cement, epoxy, and barge glue, but they didn't seem like good candidates: they either dried into a hard, brittle substance, cured nearly instantly, or wouldn't work well on foam EVA and fabric.  I settled on using Shoe Goo, a polymer adhesive that hardens into a strong but flexible rubbery substance after curing for several hours. 

Brief Thoughts: Long easy runs in marathon training

The long run is a central piece of marathon training for everyone from recreational marathoners all the way up to national-level competitors.  There are a lot of reasons why distance runners, and marathoners in particular, do long runs; these include increasing mitochondrial and capillary density, improving leg strength and resilience to the pounding of a two, three, or four-hour race, and, most pertinent to this post, to put in mileage in a low glycogen availability state.

If you aren't up on the latest training jargon, that last point just means that one purported benefit of long runs is to deplete the stored carbohydrates in your body so you are forced to burn more fat.  When your body has run out of carbohydrates, you have "hit the wall," colloquially speaking—fat is much less efficient to burn than carbohydrates, so you end up slowing down significantly.  When this occurs in a race, it's sometimes called "bonking."  This is obviously undesirable during a marathon, and one way to avoid it should be to train your body to parse out its carbohydrate stores more efficiently, sparing more for the end of the race, hence the long run as a staple of marathon training.  The long run takes on such importance in a typical marathon training plan that you'll often see runners doing as little as 30 or 40 miles a week putting in a 16-22-mile long run every week to prepare for the marathon.  Moreover, this run is virtually always done at an easy pace, or with only small segments at marathon pace.

There are a number of problems with this situation, but the one I'd like to focus on today is the carbohydrate-burning aspect.  In short, doing long easy runs is not going to deplete most runners' carbohydrate stores! Let's take a look at why.

Preparing for championship races with Renato Canova, Part III: Caleb Ndiku's training before the Commonwealth Games 5k

Workout schedules and analysis of the training of Renato Canova's athletes have become some of the most popular content on my website.  Today, we're taking a look at a short block of training done by Caleb Ndiku.  Regular readers will remember Ndiku—I analyzed Ndiku's training schedule before his victory over 3000m at this year's World Indoor Championships.  Ndiku's outdoor campaign this spring and summer included a 13:01 win at the Prefontaine Classic 5k in Eugene, a 7:31 3k in Europe, and a victory at the Commonwealth Games in the 5k.

Canova graciously provided the final seventeen days of Ndiku's preparations for the Commonwealth Games, and in usual fashion, I have formatted them into a printable schedule and translated the paces into relative percentages of race pace.  The preparations for this race are especially interesting because, as Canova remarks on the LetsRun thread in which he detailed Ndiku's training, it was written with the assumption that reigning Olympic and World Champion Mo Farah would be in the race, and thus Ndiku would need to be in peak shape to win.  Farah ended up not running, citing medical problems, handing Ndiku a fairly clean victory over compatriot Isiah Koech and New Zealander Zane Robertson.

 

Info and Disclaimer

All of the usual caveats about interpretations apply—I'm just a coach and writer, I'm not Renato Canova himself, so this is only my opinion and analysis of the training.  And I accept any responsibility for mistakes or typos.  Percentages are calculated in the "Canova" method, meaning that 90% of 5k pace, for example is 5k pace * 1.10.  Based on Ndiku's performance at the various Diamond League meets this spring, I set Ndiku's current 5k pace at 13:00 for the calculations.  Varying this by 5-10 seconds will have no significant impact on the percentage calculations.

At the link below, you'll find the training schedule, formatted, converted to imperial distances, and with paces translated to relative speeds.

Caleb Ndiku's training before the 2014 Commonwealth Games 5000m - Printable schedule