Sunday, July 4, 2010

Final Thoughts on the VFF

This will be my last post on the VFF.

Its taken up a little bit too much space on this blog for the past 6 months.

The experiences of the past several months have shown me that the VFF is a great training shoe, and an excellent way to shift into a mid/forefoot strike running style. On the off-road Half Marathon, and the long training runs at the end of the training cycle (9-11 mile long runs in the city), both my legs and lungs felt less pulverized than they had ever been during my experiences running those same distances in motion control shoes.

But I DO NOT plan on using the VFF again for distances longer than 6-7 miles, or as my race day shoes.

For me the early problems I had with the VFF's, specifically calf pain, disappeared eventually. But my feet never got used to the impact -- especially as I got into the higher distances (9-11 mile training runs). What would happen on the longer runs is that I'd have plenty of energy left everywhere else, but my feet would be so sore from the constant pounding that couldn't put the hammer down.

This doesn't mean I'm going back to my ASICS Motion Controls -- anything but that. I have no desire at this point to going back to heel striking, and I'm not going to spend money on shoes that would bring me back to that form of running.

What this does mean is that I'll probably use the VFF's for shorter runs, intervals, hill workouts, stair climbing, etc. Doing these shorter runs that are built around drills & specific workout routines will help preserve the forefoot/mid-foot running style I've developed since January. I'll probably buy a more conventional running shoe, but with a flatter and thinner bottom than motion control shoes, maybe a pair of racing flats, for longer runs, or race days. The regular running shoes (hopefully) would shield my feet from the repeated pounding I got from the VFF's, but would still let me run with a fore/midfoot strike -- preserving my knees, hips, quads, and lungs.

In the end, its not running in bare feet (what the VFF tries to simulate) that is better for you, its running with a mid/forefoot strike. The VFF is a means to achieving that end -- not an end in and of itself.


When I checked my VFF's this morning, I finally saw the damage the last run did to them.

Those yellow spots you see towards the edge of the soles are where the outermost layer of rubber has worn out. Before the trail run there was only one yellow spot. Afterwards there were two.

This hole is where the rubber wore all the way through. It wasn't like this before the trail run.

LESSON: Never use the VFF Sprint on city streets, trail runs, or any substantial outdoor workout.

I Did It...But I'm Not Doing It Ever Again...

Yesterday I finally did what I had been planning to do for the past six months -- do a Half Marathon in a pair of VFF's. So I headed down to Pacifica to do a Half Marathon trail run in San Pedro Valley County Park.

The event itself was great -- good organization, wonderful views, tough and very technical course on a single track trail.


I ran in my Sprints. It was a BAD idea. The Sprints (despite Vibram corporation marketing them as the running shoe of the VFF family) is a bit too flimsy even for city running. On a trail they are even worse. They bottoms are way too thin. What this means is that anytime I stepped on a sharp rock or an acorn it would stab into the bottom of my feet. There is also very little tread on them -- so its hard to get a grip on stone surfaces.

The weaknesses of the Sprints weren't so much a problem going up hill. Going up a long hill while trail running you either jog very slowly or walk -- no point killing yourself. So heading up the first nasty hill, I was passing people here and there. But after cresting the hill, that's when the problems occurred.

When trail running you make up the time you lost walking uphill by running balls out on the downhill. You blast your way down hill at the fastest possible speed you can go without falling flat on your face. This involves landing your feet at high speed on jagged rocks, roots, rocky surfaces, and other forms of nastiness.

On the downhill sections I couldn't do this with my VFF's. It was way too painful and too dangerous. A few times I nearly slipped and tripped. In all the rocky sections I had to walk (REPEAT - WALK not RUN) down very slowly and carefully. Just walking down was killing my feet -- if I had gone down as fast as I would have in regular running shoes my feet (and my VFF's) would have been destroyed.

Too add insult to injury -- people whom I had passed going up the hill were now blasting past me on the downhill. It was a kind of nasty poetic justice.

At the end of the day I finished 45 minutes slower than my previous time doing a Half Marathon trail run back in December up in Marin. I attribute all of this to not being able to attack the downhills.

Would this have been different if I had a tougher pair of VFF's like the KSO or the Bikila -- doubt it. While the other Vibrams do have thicker soles, its not clear that they'd be thick enough to insulate the bottom of my feet from all the nasty sharp edges on the trail. Also -- if my feet are slamemed down at high speed against a sharp edges repeatedly over the span of 13 miles, it would have eventually chewed up my feet.

Ironically -- everything else was fine. While walking uphill around mile 10, a fellow runner told me that listening to my breathing I didn't sound all that tired. While my legs are very sore and tired today, my knees and hips for the most part don't have that feeling of being completely pulverized -- just exhausted. Also my calves -- the part that usually gives out during the early days of VFF running, were fine. I'm writing this 24 hours after the run, and there is no calf soreness.

All this feeds into my final overall shtick on the VFF in my next post.