Thursday, March 22, 2012

on barefeet vs shoes

the pseudo claims of running efficiency and injury prevention as regards barefoot running are based on some faulty anthropological observations, as i've said before. the essence of these claims is that mankind has been walking/running barefoot for millenia if not longer until hard-sole shoes came about this last millenia. prior to that, most foot wear was light, thin soled, and more supple/flexible than modern shoes/boots. furthermore, cultures highly dependent on bipedal locomotion, such as nomads and hunters, tended to be very efficient and effective running in super-light sandals or totally-bare feet. and somehow these folks did it for miles on end, day after day, and all without injury.

but remember, we only test and measure those who can and still do run. we haven't evaluated all those who live in more urban environs/circumstances who cannot or will not run, some of whom made this choice not because they didn't want to be able to functoin in their respective tribes/cultures but because maybe it hurt to run when they were young, so they pursued other ventures. those who still walked and ran a lot were better built for doing so.

modern studies, some of which i have reported on, have concluded a variety of reasons to convert to light-wt, barefoot shoe designs: efficiency due to less weight and injury reduction due to re-education and strengthening of the intrinsic, smaller muscles of the lower leg and feet are two of the main reasons people promote and/or wear barefoot shoes. some of these studies are quite good; some are less so, and many have been abused by the media hype, probably as a result of press releases sent out by manufacturers of these shoes. this study, on the other hand, narrowed its scope and kept its focus on efficiency:

using runners who actually ran barefoot, so there was no adjustment period necessary, they had them run on treadmills with a variety of manipulations: barefoot with lead strips on the tops of their feet that were equal to the weight of a light-wt brand of running shoes, and other conditions, too. they found no significant difference bw going barefoot vs shod, with some small benefit to the shod conditions. the conclusions are tame - basically, if you are an elite racer wearing a lightwt shoe may benefit you. for the rest of us slow pokes, it probalby does not make much difference. (i've made similar claims about cycling equipment - other than possibly making for an easier ride, it probably won't make most of us that much faster; racers might benefit from hi priced equipment but the rest of would get equal health benefits riding a cheaper bike.)

but i must confess that i have been wearing merrel's brand of barefoot shoes for over a year and while i do not run, because of knee arthritis, i CAN run, even if only across the street, without pain in the knee or feet, something i could not do in hi priced new balance cross trainers. why? i think it's because barefoot shoes make you run on the ballls of the feet and avoid the heel impact, which shocks my knee real painfully. furthermore, as a trainer on my feet for several hours/day, my feet and legs don't hurt in barefoot shoes but within a couple hours, regular shoes cause my lower leg to ache. even my feet feel better despite having no arch support for my flat feet!

so what's my opinion on barefoot shoes, in light of this study? well, if you are interested in trying them even if only for walkng around your home or for other ADLs, see if going barefoot hurts....but enter this path gently. do an hour/day for a couple days, then two hrs/day, adding 30-60 minutes every couple days. after you've acclimated to them, try jogging, on flat, less dense - i.e. not on concrete or steps at first - surfaces, but start in 5 minute increments throughout the early accommodation runs, and keep them to short distance runs. gradually add distance, then start adding speed - this could take MONTHS but jumping into these kinds of shoes without accommodating them and the hard surfaces on which most people run, is asking for trouble. and nothing hurts a runner's overall psyche than foot and lower leg pain.

Tuesday, March 13, 2012

just to blog

sometimes you just have to write something that comes to mind. i could easily share personal life issues that would bore you almost as readily is it bores me, but this blog is about fitness and the news is always coming thru a mile a minute. so let's talk statistics - yes, that boring stuff most of us really don't understand but use when the numbers support our beliefs. btw, i don''t understand stats much either but i've had to make sense of some of the research in order to discuss issues with clients or lecture other fitness professionals for Exercise ETC programs.

let's start with this article in today's NY Times:

now, the gist of it is that a particular toxin - BMAA- that's often present in the brains of deceased humans with neurodegenerative diseases such as Lou Gehrig's or Alzheimer's is also present in shark cartilage. shark cartilage is sold and promoted as beneficial for joint degeneration and for cancer prevention, the latter of which has never been proven and has, when touted, received notice from federal authorities. the suggestion of the article, then, is that taking shark cartilage may cause neurodenerative diseases.

now, nothing in the referenced articles support this scare tactic. it is merely a hypothetical. but let me remind you that alzheimers has been around long before shark cartilage has been on the market or that shark has been in the american/western diet; and lou gehrig died many years ago, well before any american ever thought of consuming dessicated shark cartilage for bad knees. furthermore, tho one study referenced the hi rates of certain types of brain diseases in south pacific cultures that eat large amounts of sea food, there are so many other heavy metals in fish that to isolate this one amino acid is to pick at a defenseless protein when other causes can't be found.

let me suggest the following: correlation is not causation. we all learn this in stats and in classes where statistics are prominent features of the science of whatever. you may not have learned it in english 101 or philosophy 203 but even psych 100 or sociology 200 taught this principle. basically correlation means what it says - things are co-related; often one or more elements are found to some degree when one finds other elements of whatever it is one is studying. thus, as in my dissertation topic - leg length discrepancy, athletic injury, and strength imbalances - one might find that a leg length discrepancy is correlated at some statistical level worth considering when someone has an athletic injury but that it is not sufficiently correlated to any strength imbalances (that were studied); and that strength imbalances may be correlated to injury but that length discrepancies are not - making the overall correlation of the three elements so low as to say that it's hardly an issue. and my data indeed found insufficient support for my hypothesis that the three were related. BUT if the study did find them highly correlated, there would still be NO PROOF that discrepancies caused imbalances which then caused injuries. in other words, you may find them all in the same pot but not contributing to the end piece, the injuries themselves.

with that understood, shark cartilage may have an amino acid often found in the brains of people who have certain brain disorders but the amino acid itself may NOT have come from any outside source let alone shark cartilage. it may have come about as a result of some metabolic or physiologic function that went awry in the brain itself or elsewhere in the body and that it accumulated in the brain thereby contributing to the disease itself. BUT since they have yet to pinpoint the actual causes of most neurodegenerative diseases, esp the two mentioned in the article, there's also the chance that it just so happens that the amino acid itself is in the brains of some people as a result of some other more closely-linked biochemical disturbance that actually causes the degeneration.

in other words, don't be scared to use shark cartilage products; just know that they also may not work to reduce joint pain and most likely don't work to prevent or treat cancer.