Minimalist Theory according to Jeff Milliman
The big buzz in the running shoe industry right now is “minimalist” and “barefoot” shoes. Now let me first state that I am not here to detract from the minimalist philosophy – I have even been known to race barefoot quite a lot before shoes were as advanced as they are today. But, please believe me when I say that shoes are a good thing.
I started running when shoes did not have cushion so we tried to run on grass or dirt as much as possible. But as shoe technology advanced, running on asphalt became a viable option for me. While running on natural surfaces such as grass or dirt are preferable, and allow you to use a more natural minimalist shoe, if you must run on an artificial surface it is helpful to use a shoe that has more protection. When running on natural surfaces, you can get away with more natural support from your shoes (i.e. very minimalist). But when running on artificial surfaces you need more artificial cushioning and protection from your shoes.
Am I saying that if you run on the roads, minimalist shoes are out of the question? Absolutely not! While it is the case that you need some cushioning and protection if you are to run on the roads, it is equally true that your body will function most efficiently and safely in a shoe that allows it to move naturally no matter the running surface. In other words, a more minimalist shoe is a great option for all runners, but not the same minimalist shoe is right for everyone.
"...a more minimalist shoe is a great option for all runners, but not the same minimalist shoe is right for everyone."
As the buzz of the minimalist shoe philosophy has become overwhelming, many have come away with the false notion that ideally everyone should run as close to barefoot as possible. People are also left asking: “what constitutes ‘minimal’ anyway?” Is it a lightweight shoe with no cushioning? Is it less drop from heel to toe? The fact of the matter is that “minimal” is quite relative. If you have always run in a lightweight, low cushion, low profile training shoe, then “minimal” might mean that you run some days in racing flats. If on the other hand you have been using beefy shoes with 12mm of heel lift, it is probably not a good idea to move to a shoe with no heel lift and no cushion. It might be a better idea to try a more flexible shoe with 8mm of heel lift and see how that goes first. There is not one minimalist shoe that is right for everyone. But the idea is to get runners into a shoe that will aid their natural movement while simultaneously providing the necessary protection from the running surface.
"...the idea is to get runners into a shoe that will aid their natural movement while simultaneously providing the necessary protection from the running surface."
While there is not a single minimalist shoe that is perfect for everyone, the benefits associated with moving towards a more natural shoe are substantial. First, a more natural shoe is much more efficient than a beefy trainer. A more natural shoe is more efficient in that the lesser heel lift allows for a more natural foot strike. Humans are designed so that they can absorb the shock of impact when walking or running. If you wear something with a high heel lift, the natural shock absorption is disrupted. The higher heel encourages a heel-first straight-legged foot strike. This foot strike actually serves as a braking motion, which is contrary to the natural foot strike. A lower heel lift encourages a foot strike closer to the mid-foot or forefoot and a bent-legged foot strike. In this motion, your heel merely brushes the ground before the mid-foot or forefoot take the initial strike and your arch and bent leg absorb the shock and prepare you to propel forward. This results in less wasted energy as you are not having to overcome a braking motion every time you strike the ground and you are prepared to move forward.
"Well the fact of the matter is, that the lower to the ground your foot is the more stable your balance is."
Other than efficiency, another benefit to a more natural running shoe is that it is inherently more stable. This notion sounds counterintuitive. How can less shoe be more stable? Well the fact of the matter is that the lower to the ground your foot is the more stable your balance is. The higher your foot is off the ground, the less stable. On the same note, the higher the heel is in proportion to the forefoot, the more unnatural your center of balance is and you are not going to be as stable. As a result of more “built up” shoes, your body is more likely to suffer injuries from your ankles up to your lower back due to the amount of energy needed to provide stability. Conversely, the lower you are to the ground, the more stable and therefore the safer it is to run.
"While running on natural surfaces such as grass or dirt are preferable, and allow you to use a more natural minimalist shoe, if you must run on an artificial surface it is helpful to use a shoe that has more protection."
Continued...I started realizing all of this in 1977 while in college. At this time, some shoes started coming on the market that had a higher heel lift. Prior to this time, training shoes were only beefed up versions of racing shoes (i.e. they had the same proportions of heel to toe lift as racers, with only more cushion that allowed for more training). When these new shoes started coming out, I realized that they were causing runners to go through a less natural and less efficient range of motion. Therefore I started modifying my shoes, and then the shoes of teammates and friends. I would shave down the heel so that I would have a shoe that would function like a racer, but had more cushion, protection, and was more durable than my racers. As my running and coaching career continued, so did shoe advancement. As cushioning materials improved and became more durable I began to realize that my athletes and I could train in racing shoes and train at higher levels while incurring fewer injuries. But what must be noted here, is that these individuals were people who had been running almost their entire lives and their main goal was to run faster.
An example of one such runner is one of my best friends, who about 20 years ago wanted to break the 3 hour barrier in the marathon. He had put in some wonderful training, and had come very close to his goal several times. The week of his marathon, he asked me if I had any last minute advice that would help him reach his goal. I told him that if it were me, I would wear racing flats. He took my advice and ran 2 hours and 54 minutes. What he learned in the process is that he did not fatigue as badly as normal did during the last few miles (due to the fact that he was going through a much more natural range of motion). And what surprised him the most was that he was actually able to run several miles the day after the marathon, when after previous marathons he could barely walk! Again, I do not want to say that this would happen for everyone or that all racing shoes are the same. But it is true that my friend has trained in racing shoes ever since and has become a very successful coach and his athletes train in racing shoes.
I hope that from this article you have seen that I could not agree more with the trend of creating shoes that allow runners to run more efficiently. But at the same time I hope that you have heard me say that we must be very careful not to take too big of a leap at once towards the minimalist shoe unless you are constantly struggling with injuries or performance issues. The goal is to run naturally and intelligently so that you can have fun and stay injury free.