So the story goes that if you rotate shoes you get a couple benefits. First, you prolong the life the shoe by giving it time to recovery, specifically the EVA sole which they argue needs 24-48 hrs. to decompress. Second, you reduce the chances of repetitive stress injuries by moving stress points as each shoe will work different muscles and tendons. Well, both points are extremely flawed.
First, there are numerous studies that validate the point that it only takes 2-6 hrs. for cushion to decompress and not 24-48 hrs. although that is a great marketing message to get you to buy more running shoes. Second, repetitive stress injuries are very complex and if that was always a material issue then how did we run thousands of years ago when we either ran barefoot or in the same shoe until it literally self-destructed? The real result of shoe rotation is that is hampers and reduces your ability to develop an optimal gait. I say that will qualification because if you use a different shoe because of terrain, that's understandable, however, the vast majority of recreational runners run over the same easy surfaces which range from concrete/asphalt to easy packed dirt roads and trails, none of which require specialized technical running shoes (it's different if you are a hard core mountain runner then I understand switching to a shoe providing more protection).
However, let's go a bit deeper in the discussion. There's no way to avoid a discussion about "cushion" in general, most of which is EVA. This effectively leads the discussion to the impact of cushion on the human body. Cushion is not to dissimilar from a sponge and if you step on a sponge if compresses and decompresses and during that process you are "not" in balance, and in fact, you are off balance and the body, muscles and tendons are at work to achieve balance during this process. Furthermore, if you take that same step thousands of times, the cushion will mold to your foot, which as first sounds great but the impact is more imbalance and it magnifies the balancing process and not in a positive way. So is all cushion bad? No, I don't think so but the goal is to find a flat shoe (balance) with the least amount of cushion possible for your given body type. The difference, for example, in 10mm vs. 20mm in stack height is enormous.
I'd further argue that once you find a flat (as possible) shoe with the least amount of cushion you run in happily, then use that same shoe over and over and over until it self destructs because you will develop an optimal gait in that shoe. As for repetitive stress injuries, if you are running properly, then you are working the correct muscle groups (the big muscle groups) which were designed to support running. Lastly, many injuries are directly related to "dumb" running, that is, running too far, too fast, or with too much intensity on a given day. Learn how to adapt your running to what the body wants and needs on a specific day, and you'll be light years ahead of your comrades.
Cheers,
Harry
Wednesday, November 28, 2012
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So, how do you know what type of shoe your body needs? I don't have any real problems with my shoes, but I always wonder...is this the best shoe for me. It's hard for us little people to know the right thing to do. There is SO much information out there, it's simply overwhelming!
ReplyDeleteHi Lydia, the million dollar question :). This will be a long winded response so I apologize upfront but there's no short response. Running at its basic level is about balance, as is the case with any sport. If you honestly (without buying into all the current hype out there) analyze the modern shoe against the construction of the human foot, it's insane. The modern shoe is very similar to running in high heels which no one would do but we do it. If the heel is elevated 8-16mm above the forefoot, it's a high heel which means, you are immediately off balance which also means the muscles and tendons have to work awfully hard to overcome the de-stabilizing effects of that design. Then add "cushion" and just look at gymnastics. They land on a "hard" surface because it's the most stable surface and if they landed on a soft surface, it will be difficult to land balanced.
ReplyDeleteYou are right that there's a ton of information out there so I tell folks to just analyze a modern running very closely and ask yourself if the design make sense? Then, run barefoot on a nice treadmill or along the beach and then put on a pair of modern running shoes, and feel the impact . . . it's very telling.
I just point this out as a starting point. I do not preach about becoming a barefoot runner tomorrow :) and in fact, I do very little barefoot running today although I did in the past. There's honestly no justification or case for a shoe with an elevated heel . . . we were designed to walk and run with a flat sole, or at least as close to flat as possible (personally anything less than 4mm of heel elevation is pretty flat). As for cushion, this gets tricky as there's too much and too little. Too much cases too much de-stabilization and too little requires the legs to work awfully hard to absorb the impact of the landing.
With all that said, it requires "trial and error" with the goal of migrating down slowly until you find your personal "baseline," that is, the goal is to run in the most minimalist shoe, meaning the least heel deviation, least about of technology, and the lightest shoe possible. That specific answer will vary runner to runner and it takes time because the body has to adjust down to each muscle and tendon but actually the adjustment is the body going back to how it was originally designed.
I'll be honest . . . this adjustment took me years but at the end, I'm such a better runner. Over years, I went from, for example, a 22 min. 5k to running 17 min. 5k but importantly, I learned how to run injury free and there's several reasons for that including reasons having nothing to do with shoes but the impact of shoes was a major issue.
DeleteI got stronger and more efficient because if you run correctly, then you stress the correct muscle groups which are the big muscle groups (calves, quads) and not the small muscle or tendon groups like the achilles and knee which unfortunately most runners do stress and it results in serious injury. We were designed to put stress on certain muscle groups but you need to be as perfectly balanced as possible to put the stress on the correct areas and not the wrong areas.
Lastly, the kicker which will cancel out the vast majority of runners. To begin the "trail and error" process, the commitment level must be very high with the ultimate goal of running 6-7 days a week because it takes consistent repetition to start to understand your body. Only running 3-4 days a week and having break in-between, disrupts this process and you end up taking many steps backwards. I understand there's life in the way and that requires a prioritization as to where running fits in your life.
For me, it's not about running, but about being in shape so I can be a better husband and father and runner is the medium I choose to become fit so my commitment level is extremely high because it's a commitment to not only myself, but my wife and kids. And, I'll admit, I'm vain so it's fun to be a 42 yr. old man totally in shape with flat stomach weighing the same as I did in high school while I look at my similar aged friends with big beer bellies :) . . . just being honest and staying fit has its rewards with respect to the martial relationship. My wife would love me either way but being fit definitely doesn't hurt :).
Ok, so I'm way off topic, but not really as it all relates. What you put on your feet is a serious thing and more serious than 99% of runners realize.
I've been lucky to learn from most very talented runners and the basic lesson was "run in the most minimal shoes possible taking into consideration the weather and terrain." Most of us rarely run on the nasty mountain stuff as most of us run on some combination of concrete, asphalt or soft dirt roads and trails so terrain isn't that big a factor "ONCE" you learn how to run correctly but when running correctly you land very softly with a good cadence level and balanced (most runner crash their feet into the group; I see it every day and it's painful to even watch and I was one of those runners). Over time, you will find your baseline and the specific shoe design for your body but your body will change if you are a committed runner so that's why there's so much trail and error (I'm 40 lbs. lighter than I was when I started running 7 yrs. ago).
Harry
Thanks Harry for your candor. Although I am no where near as eloquent...I would tend to agree with everything you've said. I've been slowing working my way down to a more minimalist shoe. I too am happy to run, for the most part injury free. I guess that should be a good indication that I'm headed in the right direction. I'm so glad that you are writing on your blog more. You have such an interesting way of putting your thoughts into words. I appreciate it. Thank you!
ReplyDeleteMy pleasure Lydia. Have a great weekend.
ReplyDelete