Wednesday, February 10, 2010

Vibram Five-Fingers, 1200 Miles in

Most reviews of running in Vibram Five-Fingers “shoes” are necessarily based on a few days to a few weeks of experience. Journalists, of course, rarely have any longer time horizon available to them since they need to get something out promptly. My own first review was based on a couple of months of experience; this is a follow-up report now that I’ve been using them for some 8 months and 1200 miles.

“Barefoot” Running?
Do I now consider myself a “habitual barefoot runner”? No! I’ve definitely gotten solidly past a transition period away from conventional running shoes and now run (and do most things where I need shoes and can get by without more complicated foot protection) exclusively in my Five-Fingers. However, my feet don’t have good abrasion resistance yet. I can run 3–4 miles on “good” surfaces such as real or artificial turf, smooth dirt, rubber track surfaces, and the like, and up to about 2 miles on rough surfaces such as gravel or rough asphalt or concrete, but for longer distances, I need to wear something on the bottom of my feet to avoid blisters and hot spots. I have no plans to run any organized events barefoot anytime soon, though I will continue to go barefoot for less strenuous activities whenever I think it is safe to do so.

That said, of course, running in minimalist shoes, whether Five-Fingers, moccasins, sandals, or other commercial attempts to provide a near-barefoot experience, does allow you to mimic a lot of the characteristics of barefoot running with our modern typical fragile foot bottoms. Musculature and fat pads adapt more quickly than abrasion resistance, though these, too, require some real adaptation leading to a lot of early problems for people that try to do too much too soon.

Running Style
Whether running barefoot or in minimalist shoes, you rapidly discover (if no one tells you first), that you probably want to move away from the sort of heel-strike running gait that most shod runners are taught to use or use instinctively for anything beyond short sprint distances. True habitual barefoot runners (such as those who grew up not wearing shoes at all) do not use a heel strike. The high shock associated with landing on your heel without any possibility of shock absorption by the foot causes heel bruises and other unpleasant feelings (such as more strain on the knees) if you don’t have any shoe structure to absorb the shock of heel-strike running. Sprinters run on their forefeet and generally don’t let their heels touch the ground at all. But for longer distances (more than about 30 seconds of running), most runners do allow their heels to touch even if they don’t land on them.

There are many possible variations on the exact gait one can use when running in minimalist shoes. Personally, I strive for efficiency as an endurance runner (I’m definitely not a sprinter), and I find that the gait I use for most routine running keeps my feet low to the ground, and my stride length perhaps a little shorter than it used to be. I land first (just barely) on the inside edge of my forefoot and roll the ground contact across the ball of my foot and then back along the outside edge to my heel which just touches the ground with minimal force and then comes back up to reverse the movement until the foot leaves the ground again. This motion, of course, makes full use of the natural structure of the foot and provides maximum opportunity to use all available ligaments, tendons, and muscles for shock absorption, energy storage and release, and push for the next step. I think this is true regardless of your foot type (within normal variations). I happen to have rather flat arches, but I don’t think my minimalist shoe running style is particularly different from that of someone with very high arches. I haven’t yet seen any data on wear patterns for the soles of minimalist shoe runners. Anecdotally, there is still some variability in the location of maximum wear, though much less so than is observed for “normal” running shoes. I think I am seeing what I think is the most common pattern, finding that the point of greatest wear is on the inside ball of the foot and the big toe.

[Addendum 11 February 2010: (thanks to Tuck for making me look more carefully at Daniel Lieberman’s pressure-plate video) It seems that exactly where you naturally strike on your forefoot depends on your particular foot structure. I have rather flat arches and a tendency to pronate (turn my foot inward) which is manifested in a tendency to wear the inside edge of the heel of shoes when running with a heel-strike gait. In a forefoot gait, I land first on my first metatarsal and then transfer weight to my big toe, then across the rest of my metatarsals. Daniel’s pressure plate video (presumably of himself running) shows initial pressure buildup under the fourth metatarsal with a roll toward the first metatarsal. Presumably he does not tend to pronate and likely has higher arches than I do. If you don’t have access to time-resolved pressure plate data recording equipment and don’t want to wait a few hundred miles to analyze shoe wear patterns, here’s a simple trick I found that should tell you how you should probably land: Stand up (barefoot) with your leg forward. Point your toe (i.e., bend your foot forward), but keep your ankle in a neutral position laterally (don’t consciously turn it either in or out). Now touch your foot to the ground. When I do this test, I touch with my first metatarsal and/or big toe. Cynthia, on the other hand, who has high arches and no tendency to pronate, touches on the fourth metatarsal. While there are some people who try to get everyone to do the “right” thing meaning the same thing they do, it is my belief that there is no right or wrong way to use your foot. You should do what is comfortable and natural for your particular bone and ligament structure. For me, while I could force myself to land on my fourth metatarsal, it would be an unnatural thing to do and likely cause undesirable side effects in the form of muscle strain.]

Landing on your forefoot results in a gentler landing with less force against the ground, less shock on the knees, and less noise. You become the proverbial Indian brave, able to run quietly through the woods in your moccasins (or equivalent). In fact, one of the ways that you can further train yourself to reduce stress is to aim for the quietest running that you can achieve. There is still a range of impact force that can be used with forefront landing, and a good way to aim for lower impact force and greater running efficiency is to listen to your running and try to keep it as quiet as possible. You may need to ramp up the noise a little bit again when you’re out to get maximum speed, but for most routine running, quieter is probably better.

While I am primarily a trail runner by temperament, one surprising (to me) consequence of switching to a forefoot landing habit is that running on hard surfaces such as roads is no longer something that I shun. Since I am now a gentler runner, long distance pavement pounding is just not nearly as stressful as it used to be, and in fact, all else being equal, I now find myself seeking out the smoother harder surfaces rather than running on the adjacent dirt if both are available.

Another aspect of running in minimalist shoes is that you are less constrained to hold your foot in a particular orientation relative to your leg. Most of the time this doesn’t matter all that much. But if you happen to be contouring along a steep hillside or placing your feet on the sides of a deeply rutted trail, you may find yourself needing to adapt to a surface that is far from perpendicular to your leg. In shoes, this can be an unpleasant ankle twisting (and even ankle spraining) experience. But with Five-Fingers shoes you can take up most of the extra bending in the foot rather than the ankle with structures that are much better adapted to the bend than is the ankle. This is an aspect of barefoot/minimalist shoe running about which I’ve seen very little comment. I discovered the phenomenon accidentally one day when I found myself running along the side of a very steep hillside, cutting across an open field. I suddenly realized that the running was much easier and much less stressful on the ankles than I would have expected.

Muscle and other Soft Tissue Development
Any change in running style—whether due to a change in footwear, compensation for injury, change in running surface, distance, or terrain—will stress muscles in new and different ways. Most notably, switching from heel-strike to forefoot running increases the dependence on muscles associated with the feet. The strongest of these muscles are actually located in the lower leg and connected via an elaborate system of ropes and pulleys (a.k.a. tendons, ligaments, and fascia) to the bones of the foot. Runners who transition too rapidly from heel-strike to forefoot running often experience at least pain if not outright injury in their lower leg muscles as well as their Achilles tendons and plantar fascia. As with any transition, the key is to start slowly—less than a mile for the first few days, increasing gradually as muscles allow. Plan on a minimum of 2–3 weeks of gradually increasing distance, speed, and difficulty, and preferably at least twice that long. Back off if you experience any significant pain. If you want to supplement your actual running with other training, then anything that puts you on your toes (calf raises, skipping rope, dance or fencing exercises) can be useful cross training.

How did I fare during my transition? Well enough. I had an enforced reduction in mileage about the same time I made the transition due to an unrelated injury. I’m finally fully recovered from that injury, and I actually think that forefoot running and the associated reduced knee stress helped me recover more quickly and increase mileage again more quickly. I’m presently contending with a mild case of plantar fasciitis in one foot—nothing that is limiting my running at all, but annoying all the same. Again, I find that forefoot running is less stressful on the injured tissues.

Of course, one of the main things that people wonder about, especially for trail running, is the issue of how you can run on rough surfaces without much cushioning from a shoe. Running on surfaces with a lot of small stones (rocky trails, gravel roads with relatively little actual gravel) is the most challenging. It takes a while to toughen the pads on the balls of your feet, but it does happen. The improvement is gradual and takes easily 3–6 months depending on how you train. Eight months out, I find that surface that used to leave my feet feeling beat-up after a few miles no longer bother me at all. I can run 10+ miles on very challenging trail surfaces and come home feeling unaffected. A recent 50K run that included a lot of gravel trail still left me feeling a bit worked over, but my feet were fine again by the next day.

The older models of Five-Fingers shoes (including the KSO model that I wear) have practically no tread or padding in the sole. In response to customer feedback, newer models incorporate some tread which also provides a little more damping out of the running surface roughness. Since I haven’t had an opportunity to try running in the new models, I can’t comment except to say that, now that I am well-adapted to running with the older thinner soles, I don’t feel any particular desire to have more protection under my feet than what I’ve got now. From a marketing point of view and the usual sort of instant gratification that many customers will want, I’m sure that a bit more sole will be a good thing; for more experienced minimalist runners like me, it doesn’t seem that more sole has any compelling attractions.

I also noted an unexpected pattern to the toughening of the pads on the balls of my feet. There is a transverse arch across the ball of the foot, and I, at least, expected that not much would happen in the middle of the arch (behind the second toe), thinking that the primary stress would be on the outsides of the arch. In actuality, the reverse happened. The most toughening occurred precisely in the middle of the arch, and there even tends to be some slight callous development there! Apparently, the transverse arch flattens completely on impact and the middle experiences as much or more force than the outsides even though the initial contact and maximum sole wear points are on the outside.

As I just noted, Vibram has recently introduced newer models that include more familiar looking shoe bottoms that have some lugs that provide both more padding and maybe more traction. After 1200 miles of running on varied surfaces including concrete, asphalt, rubber, dirt, mud, sand, rock, turf, fields, etc., I can say that I have almost never felt at a loss for traction in the KSO model soles. These soles are smooth flat rubber with laser-cut zig-zag patterns that increase grip on smooth surfaces. The only surfaces that I have found difficult to deal with are those with thin slippery mud which are challenging in any footwear (though probably respond better to lug soles than smooth soles). Deeper mud and soft sand/ash present no difficulty—the toes work very well to provide good grip and traction. Wet surfaces are generally not a problem—the rubber grips well. I don’t recommend Five-Fingers shoes for snow and ice, but under such conditions you probably want more thermal protection anyway, never mind the traction issues.

Foot Protection
Minimalist shoes clearly provide less protection for the foot against all sorts of insults. You wouldn’t want to wear them anywhere where normal safety practice would dictate steel-toed safety shoes, for example. You won’t get much protection from ankle twists, kicking hard objects (rocks and roots), sharp objects, others stepping on your feet, etc. If you need arch support or ankle support, you won’t get it (though some people who have failed to get much relief from arch-related problems with all kind of expensive orthotics have found that going minimalist instead actually turns out to be more beneficial).

So what’s my track record after 1200 miles? Pretty good and getting better! Early on, I caught one little toe on a root and wrenched it badly enough that it hurt for a couple of weeks, but that’s probably the worst thing that’s happened. I’ve also kicked a handful of rocks and roots, especially running in poor light. I have to consciously work on lifting my feet more when I can’t see the trail surface very well. I’ve poked my feet into an assortment of sharp sticks now and then, enough to do some damage to the shoe uppers, but not enough to break skin. Not surprisingly, the more you run with minimal protection, the more you instinctively avoid problems. Just as I’ve found that my rate of falling (never very high) has gradually decreased over the years, my rate of minor foot trauma has declined to almost zero over the last several months.

One of my most annoying problems as a shod runner was toenail bruising. Long downhill runs where you are constantly jamming your toes against the front of your shoe cause the most trouble. Even with careful shoe sizing for plenty of toe room, careful toenail trimming, and various aids in the form of taping, toecaps, tubes, and the like, I usually found myself losing toenails due to such bruising a few times a year. Hilly ultra-marathons generally did the most damage. This was probably the single most important factor that drove me to try Vibram Five Fingers in the first place. In the last eight months I still lost one toenail, but it was the result of kicking several rocks in a row while running in the dark, so I’d have to argue that it was really my own fault. I just don’t have toenail jamming issues with Five Fingers footwear. You fit the shoes small. I wear at least a size 44 (European) in most running shoes, but only a size 42 in Five Fingers. Your feet don’t slide inside the shoe. The front of your foot between the toes hits fabric and prevents the toes from jamming into anything.

Five Fingers shoes are usually worn without socks, though they can also be worn with toe socks such as those sold by Injinji. I started out wearing socks more often than not, and especially for runs of more than about an hour and when the weather was warmer (my feet tend to sweat more in hot weather). As time has gone on, I wear socks less and less; I just don’t need them. I almost never wear them for runs of less than two hours now, and I’ve done a full (winter) 50K without socks. One key to running without socks is to remember that the shoes, in effect, become your socks. So just as you wouldn’t wear socks again after a long run without washing them, you need to wash your Five Fingers regularly. You also need to make sure that your feet are really clean before you stick them into your Five Fingers. I regularly use a pumice stone to remove all surface debris from my feet including any sticky dirt and grease. That keeps the inside of the Five Fingers much cleaner and minimizes accumulation of junk that can cause abrasion. I wash my Five Fingers after any long run, any muddy run, and any very dusty run, and at least once a week regardless. After my 50K run, I did have a couple of minor blisters that I hadn’t realized I’d gotten. They were on the inside side of both feet in the arch region at a seam. I’ll probably opt for socks on future 50K+ runs just to protect myself from this particular hazard.

Keeping Stuff Out
The KSO model is named for “keep stuff out.” It has elastic fabric over the top of the foot that fits snuggly. It works! I’ve never had to stop to take my KSOs off to remove debris. I can’t say the same of any other shoes I’ve ever run in. KSOs still don’t keep everything out, though. They don’t keep water out, and they don’t keep fine dust out. After running in dusty conditions, your feet will look like you have dirt socks on. But I’ve never had any trouble either from dust or from wet feet. Neither has caused any harmful chafing. I consider myself fortunate to have ended up with the KSO model; other runners I’ve talked to that have ended up with other models that don’t have fabric over the top of the foot do have problems keeping stuff out.

Shoe manufactures would like you to believe that you need to replace your running shoes every few months or every few hundred miles whichever comes first. I never really bought into that plan, running happily for many months and miles in nominally worn-out shoes. Nevertheless, I am still impressed by how few signs of wear my Five Fingers show after 8 months and 1200 miles. They should be good for many more miles to come. That’s not to say that they have been completely problem free. There have been a handful of holes and seams to repair particularly wear I’ve poked the fabric with sticks. These are easy repairs to make since the material is just a cloth fabric that is easily sewn. The soles are holding up well. There is visible wear, but since there are no lugs to wear off, the wear is spread over more surface area. I have not yet needed to add any material to the soles and may not need to over the life of the shoes. As yet, I still can’t tell what the ultimate end-of-life failure mode is likely to be.

The most serious design flaw from a durability point of view in the KSO model is the strap and the slot through which the strap passes on each side of the foot. The strap is made from a relatively thin nylon fabric, and the slot is reinforced with a hard plastic resin. The nylon rubs against the edge of the slot and wears through after a while. I have so far dealt with the wear by reinforcing each strap where it goes through the slot with some thin leather. If I ever have to actually replace the strap, I will try to find some heavier duty material to use. But if I were to change one thing in the design of the KSO Five Fingers, it would be the choice of materials for the straps and slots.

Another weak point in most running shoes is the insoles. These often wear out before the rest of the shoe and need to be replaced. However, with my careful cleaning habits (both my feet and the shoes), I see no signs of wear at all yet on the insoles of my KSOs. When I wash them, I am careful to clean the surface of the insoles of any accumulated dirt and grime. I’m sure this helps. In fact, I suspect that the combination of clean practices and the natural tendency of the KSOs to keep stuff out are the primary reasons for my good experience.

The newer models of Five Fingers intended for trail runners have switched to leather uppers. While I haven’t tried these out, I don’t presently view this as a positive change. I like my thin elastic uppers. They have proven to have adequate durability and are easily repaired when damaged, they breath easily to keep my feet cool, and they can be quickly washed and dried. I am skeptical that leather would perform as well.


There is an ever increasing number of articles and blogs about barefoot running, Vibram Five Fingers and the like. A selected bibliography includes:,32068,62885933001_1955910,00.html,9171,1955580,00.html