Microbiome analysis is coming soon to a doctor near you. Microgenomics is going to be part of nearly everyone’s future. This week Nature magazine published an article which indicates that at least part of the action of the anti-diabetic medication Metformin may be occurring via the microbiome. At the least there is a dramatic difference between the gut microbiota between those with type 2 diabetes (T2D) treated with Metformin (T2D-Metformin+)and those not treated (T2D-Metformin-).
The article has an excellent discussion both of the direct effects of Metformin and the indirect effects and potential interactions of various gut bacteria
There is significant evidence that exercise is helpful in lowering one’s risk of dementia by regular moderate to vigorous exercise. And every month a plethora of articles appears reporting on positive impact or no impact at all on a variety of factors from diet and supplements to exercise.
A number of studies have indicated that starting and maintaining an exercise program has been helpful. But, we also need to define what may not be helpful. Exercise below a certain aerobic level, may just not count as preventative exercise for dementia and cognitive decline.
And I realize my bias in favor of exercise, so I must admit that some reviews have found the evidence is weak that exercise is helpful in avoiding cognitive decline.
Reported studies need to be subject to evaluation. One can not blindly accept the authors’ interpretation of the results. The results and protocol need to be rationally evaluated in an absence of hype.
I’m not sure that a recent study by Sink et. al. which did not find a positive correlation between activity and cognition was scrutinized thoroughly in the media. Looking closely at this study we find that they used a good number of patients and controls. But we see that the inclusion criteria of being able to cover 400 meters in 15 minutes is not what many would consider to be an aerobic exercise activity. The study was restricted to those over 70. And the data was not gathered using a Fitbit, Pedometer, GPS motion detector or observation. The data was self-reported.
So what do we know as a result of this study:
Being able to move at a speed of 1 mile/hour for 30 minutes (400 meters in 15 minutes) several times a week is not enough exercise to measurably diminish cognitive decline (it may have other benefits though).
Data acquisition by self-reporting may not be optimal. An objective measurement should be used in conjunction with a device to do and record these measurements.
The life style changes here may have been too little and too late to have an impact.
Commencing exercise prior to age 70 may be better than beginning later. If beginning later, results may only be seen if the individual is capable of exercising a moderate level.
Media coverage is often limited in interpretation and assessment of the meaning of a study’s results.
In a predefined subgroup of those aged 80 and over and with worse starting fitness they did find an improvement in “executive function”.
“Despite the lack of overall benefit, our prespecified subgroup analyses of participants aged 80 years or older and those with lower baseline physical performance demonstrated that the physical activity group had better performance on executive function tasks than those in the health education group at 24 months. This finding is important because executive function is the most sensitive cognitive domain to exercise interventions,40 and preserving it is required for independence in instrumental activities of daily living. Future physical activity interventions, particularly in vulnerable older adult groups (eg, ≥80 years of age and those with especially diminished physical functioning levels), may be warranted.”
The authors did consider as the first possible explanation that the exercise level was insufficient to produce changes in the cognitive measures, but this escaped the media blitz. In reading the article, conclusions and discussion, the study was well designed, properly randomized and controlled, used an adequate sample size. The possibilities leading to the observed results were thoroughly discussed. But again, the subtleties were not discussed in the media and the headlines you saw were that exercise was not useful in preventing cognitive decline. As with most studies the media would lead you to believe that the current study overturns all previous thinking and is the only thing to follow.
Bayesian reasoning allows for new information to be added into the mix of the prior thought and research on any topic. That should be done and the meaning of that should be clear to anyone writing about science literature. One study doesn’t usually replace all thinking, it is added to it in that successive approximation of the truth that we reach for through science.
So the same recommendation to exercise, in my mind, holds. It still has the most evidence pointing in its favor. And for those older individuals who are not able to exercise as vigorously, exercise is still likely to have positive impact on mood and other neurological and physical functions not measured in this study.And I’d suggest more education on EBM and study evaluation for those charged with distributing results of medical studies. And please read the study.
Erickson, KI, Barr, LL, Weinstein, AM, Banducci, SE, Akl, SL, Santo, NM, Leckie, RL, Oakley, M, Saxton, J, Aizenstein, HJ, Becker, JT, Lopez, OL. (in press). Measuring physical activity with accelerometry in a community sample with dementia. Journal of the American Geriatic Society.
Weinstein, AM, Voss, MW, Prakash, RS, Chaddock L, Szabo, A, White, SM, Wojcicki, TR, Mailey, E, McAuley, E, Kramer, AF, Erickson, KI. (2012). The association between aerobic fitness and executive function is mediated by prefrontal cortex volume. Brain, Behavior, and Immunity, 26:811-9.
Erickson KI, Miller DL, Roecklein KA. (2012). The aging hippocampus: interactions between exercise, depression, and BDNF. Neuroscientist, 18: 82-97.
“Cognitive decline is one of the most pressing healthcare issues of the 21st century. Worldwide, one new case of major cognitive decline (ie, dementia) is detected every 4 s. Given that no effective pharmacological treatment to alter the progress of cognitive decline exists, there is much interest in lifestyle approaches for preventing or treating dementia. Ideally, such strategies should be cost-efficient and widely accessible at a societal level to have the largest benefit for older adults with varying income and functional status levels.
One attractive solution that aligns with the above criteria is exercise. However, despite a large and consistent pool of evidence generated over the past five decades linking exercise to improved cognitive functions in older adults,2 there is a reluctance among academics, healthcare practitioners and the public alike to embrace exercise as a prevention and treatment strategy for cognitive decline. For example, the National Institutes of Health (NIH) consensus statement from 20103 concedes that there appears to be preliminary data to support the efficacy of exercise in improving cognitive function. However, they caution that there is currently no strong evidence to suggest that modifiable lifestyle factors can alter the trajectory of cognitive decline. Adding fuel to the fire are publications such as a 2013 systematic review of randomised controlled trials (RCTs) (prior to 31 October 2011) reporting ‘weak’ evidence for the effects of exercise on cognition.4 We must highlight that the search strategy used in that systematic review failed to capture many pertinent papers providing evidence from RCTs that exercise promotes cognitive and brain plasticity not only in healthy older adults but also in those with cognitive impairment. Furthermore, there are a number of animal studies that provide insight into the molecular and cellular mechanisms by which exercise promotes neuroplasticity.”
I’ve found what I am sure is the best podcast on running. The podcast is put on by Runnersconnect and hosted by excellent and ever improving, elite marathoner Tina Muir.
Tina is knowledgeable, ever prepared, sounds great, and conducts a wonderful interview each week. Runners Connect has interviewed many fascinating people from the running community. Among those I’ve listened to are Dan Lieberman, Chris McDougall, Tim Noakes, and Jack Daniels. Each week there is another interview with someone who has a special take on running and from which you can learn.
This week a podcast in which I was interviewed has gone online. The interview covered a lot of ground. We did not review the questions in advance. Instead we did wing it. Free range always sounds best to me. Tina was well prepared and asked questions that led to many different areas.
I hope you find the podcast interesting. It is likely to contain information you haven’t heard before and likely not quite what you’d expect. If what you wanted wasn’t included, there are so many other great podcasts, I have no doubt you’ll discover a good number that you’ll enjoy.
Is There Really A New Exercise Which Will Cure Plantar Fasciitis?
This study showed no benefit at 1 month, 6 months and one year. There was only a benefit noted at the 3 month datapoint, which then disappeared.
Highly touted High-Load Strength Training Shows No Benefit In Long Term
Last fall, you may have read in the New York Times that an article had been published in the Scandinavian Journal of Medicine & Science in Sport (August 2014) discussing the benefit of high load strength training for plantar fasciitis. The NY Times then described the wonders of this “one simple exercise” in alleviating the pain of plantar fasciitis. The implication was that this particular exercise was the only thing that was going to work. The exercise is done while standing on one foot on a box with the toes dorsiflexed on a rolled up towel. Although if you use a section of the New York Times rather than using the entire paper for your bird cage that may have equivalent effects.
If you take enough data points you might very well be able to prove anything. You may even believe what you see with that limited subset of data. (See the body of work saying there is no human contribution to climate change using limited data sets and cherry picked sources.)
How Large, Precise and Lasting Was the Treatment Effect?
This question is a basic question asked in the American Medical Association’s Guide to the Medical Literature, subtitled “A Manual for Evidence-Based Clinical Practice”. We don’t find the component parts of this question impressively demonstrated in this study.
The main problem is that the article (Rathleff 2014) found a significant improvement ONLY at 3 months (between the group performing the one leg calf raise and those performing a stretch that I’m not fond of). Both groups used “shoe inserts”. Another problem is that was called the control group was a comparison and not a control group. We’ll continue to use their term.
At 1 month, 6 months and 12 months, there were no significant differences or benefits of this exercise over the control group which just used one stretch and shoe inserts. If we found an exercise (like flossing) that made us feel better only at age 30 and gave us fewer cavities and better gums but only at age 30, there would be no benefit over other exercises that worked equally well for age 20, 40, 50, and 60. There would be no study or media attention given. But with the dearth of truly useful evidence based sports medicine the insignificant gains significance.
Most would like to use a treatment that enables them feel better in 4-6 weeks and at 4 to 6 months. The 3 month data point as a single marker is not useful.
There were not many people in this study. Only 24 in the study group and 24 in the control. Using statistical methodology to determine the minimum number to detect a difference in the functional index which they used they required 23 patients in each group. (While the use of “intention to treat” analysis is laudable, can you imagine an approach to cancer treatment being based on a study such as this with only n=24, several dropouts and improvement over a comparative treatment only present at the 3 month mark? Impossible!)
From Ratliff et. al. (2015): “Based on a previous trial, we used a common standard deviation of 18, which showed that 23 patients were needed in each group to detect a statistical difference (power 0.80, alpha 0.05) (DiGiovanni et al., 2003).”
They began the study with 24 in each group. There was a higher drop out number on the study group. Looking at the high-load strength training group there were n=22 measured at 1 month, n=18 at 3 months, n=17 at 6 months and n=18 at 12 months. At the 3 month and beyond time points they were below the levels pre-determined for measuring a detectable difference between groups.
So here we have a study of a few people who were improved in comparison with another control group for “one brief shining moment” which quickly passed. Both groups were ultimately better after 1 year but did not demonstrate a superiority of one treatment over the other. The study design is impeccable. The statistical analysis is elegant. But, the subject number is quite low and the results are clearly open to a different interpretation.
Will this exercise be helpful to some people? Yes it will. Will it be helpful to all and is there a unique benefit demonstrated by this research. No, it is not and there is no unique benefit to this exercise. There is only evidence for a briefly lasting one in this extremely small study which was seen only at the 3 month mark. Not before and not after.
So the hype on this study is just that – media hype with no basis in the evidence contained in the study.
DiGiovanni BF, Nawoczenski DA, Lintal ME, Moore EA, Murray JC, Wilding GE, Baumhauer JF. Tissue-specific plantar fascia-stretching exercise enhances outcomes in patients with chronic heel pain. A prospective, randomized study. J Bone Joint Surg Am 2003: 85-A: 1270–1277.
Digiovanni BF, Nawoczenski DA, Malay DP, Graci PA, Williams TT, Wilding GE, Baumhauer JF. Plantar fascia-specific stretching exercise improves outcomes in patients with chronic plantar fasciitis. A prospective clinical trial with two-year follow-up. J Bone Joint Surg Am 2006: 88: 1775–1781.
Lemont H, Ammirati KM, Usen N. Plantar fasciitis: a degenerative process (fasciosis) without inflammation.
J Am Podiatr Med Assoc 2003: 93: 234–237.
Pribut SM, “Current Approaches to the Management of Plantar Heel Pain Syndrome” J Am Podiatr Med Assoc, January 1, 2007; 97(1): 68 – 74.
Pribut SM, “The Top 5 Running Injuries: Part 2” Podiatry Management, June/July 2013, 181-192
Pribut SM, “Challenging Running Injuries: Be Knowledgeable” Podiatry Management January 2010, 157-166.
Rathleff MS et. al., “High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up.” Scand J Med Sci Sports. 2015 Jun;25(3):e292-300.
Thomas JL et. al., “Diagnosis and Treatment of Heel Pain: A Clinical Practice Guideline-Revision 2010”, J Foot & Ankle Surgery 49(2010) S1-S19.
Summertime is when many begin training for a fall marathon. But whatever season it is you read this, here are some training tips to keep in mind.
Train within your current fitness level. Your safe training speed limit will vary from one distance to another.
Train at different distances and speeds.
Forget the 10% rule while you build up your distance for marathon training. I recommend a two weeks gentle increase followed by a drop back in the third week. Then you can pick up where you’ve left off. This is called “two steps forward, one step back”.
Aerobic conditioning should come before speed. Consider going for aerobic conditioning, strength, and speed in that order. Arthur Lydiard was one of the first to systematically recommend this in the order o: Distance, Hills, Speed.
Get adequate rest. Make sure you rest after hard workouts and be sure to try and get a good night’s sleep.
Pay attention to your nutritional needs. Be sure to get adequate nutrition in a healthy balanced diet. Assess your needs. If you are diabetic, fine out what you need to do. If you are overweight, determine your real caloric needs. Find out where you are going wrong. Seek advice on a sensible diet. Follow the diet, document what you eat, and weigh your portions. If you have other eating issues, assess it and be honest. Get help if you need it. Don’t cut calories or relatively cut calories by working out hard without replacing your needed nutrients.
Gradually ease into your speed work. Begin with small speed spurts 100 meters, 200 meters scattered into a longer run after a warm up of a few miles of easy running. Later add in speed play, fartlek and then defined intervals. Tabata workouts are fine for fitness enthusiasts but won’t do much for your marathon training.
Use the running shoe, running stride, and foot strike that works best for you.
Pay attention to your body. Don’t ignore pain, learn from it. Know what is normal and what is not normal. Seek professional advice if it is not getting better.
Don’t forget to taper before a race and reverse taper after the race.
Laces help keep your shoes securely on your foot. They should apply pressure evenly and appropriately. Not too tight, not too loose. Just the way the story Goldilocks and the Three Bears would have described it.
Once you have found the perfect lacing system you are sure to discover it changes before very long. Running shoe manufacturers often change the position, orientation and spacing of the eyelets and the lacing system. One would like to believe it is an evolution to greater comfort, efficiency and fit. But appearance and marketability plays at some role.
Over the past few years though, the lacing system that many manufacturers have been adopting returns to a long established standard and is much easier to modify.
Selected Lacing Systems:
Conventional diagonal (Chevron)
Reduced Pressure Parallel
Skip Lacing Pattern
Loop Lock Lacing
Double Lacing (for wide forefoot and narrow heel)
What Problems Can Laces Cause?
Too loose overall:
Foot slips around in the shoe
Posterior Tibialis tendinopathy
Flexor Digitorum Longus tendinopathy
Too Tight overall
Parallel lacing can help
Anterior ankle pain
Cure : lower lace by an eyelet
Midfoot compression or hot spot
Pain in midfoot
Compresses nerves and tendons
Cure : skip lace pattern
Make sure you remove the laces from any “tongue guide” loop
Tight toe box
Aggravate incurvated toenails
Band elastic laces
Often too loose
Barrel clips or locks
Can feel like big lugs banging up against your foot
I’ve just finished an interview with a very fine Washington Post reporter on cold weather running and been inspired to make sure my tips are up to date.
Winter running is something that long time runners will do because they like being outside. It is not a time to begin an outdoor running program. And you need to be in good health and be aware that if you are over 40 or have heart problems you should have your physician’s ok. Cold weather winds blasting the face can slow up your heart and adversely affect your cardiovascular system. Every winter an enthused oldster, and sometimes not so oldster shovels their driveway and has a serious heart attack. So, as they say, “be careful out there”.
But if you are healthy and used to running in the cold, you will find it refreshing. In my area we do not have any bad air days during the winter months. You’ll find the same mental and emotional effects from running as you are accustomed to getting.
So with that in mind here are some winter running suggestions:
1. Cover your head, hands, and feet with care. Dress in layers. Use lightweight wicking fibers as the layer closest to your body. Wind blocking materials are great for an outer layer.
2. Keep your feet dry. Wear socks made of synthetic fibers that wick moisture away from your skin to help prevent blisters, athlete’s foot, and cold injuries to your foot (immersion foot, frostbite, etc.).
3. Protect your skin and eyes from UV solar damage which can cause premature aging of the skin and eye damage. Use sun block and moisturizers as appropriate. UV exposure is not good in the winter as well as summer. Sunglasses during mid-day runs can be helpful.
4. Don’t forget to replace your fluids on long runs.
5. Make sure you have the energy to finish your run. Fuel up lightly 30 minutes before your run.
6. Warm up slowly and gently before your runs and especially before doing speed work.
7. Wear sport specific running shoes. Fit your running shoes or other sports shoes with the type of sock you intend to wear them with. Do replace your running shoes often. Replace them at least every 350 – 450 miles run. Be sure to transition very slowly and carefully to new running shoes, particularly when switching to a dramatically different style of shoe.
8. Don’t run on ice. Beware of Black Ice on the pavement.
9. Be careful running in low light conditions. Beware traffic and uneven pavement. If you have any balance problems run in good lighting conditions.
10. Don’t do speedwork in bone chilling cold. You are risking injury. Most wise runners use this season for maintenance runs.
Two articles currently up on the Runner’s World news and blog areas take opposite approaches to Achilles tendon problems. One cites a study of normal individuals who were asymptomatic and measured “load” in the Achilles tendon and concluded that there would probably be no help given by a heel lift. This was not a clinical study of treatment however and it has no validity regarding statements made about treatment. In fact the least helpful part of many studies is in the “discussion” part of the study where the authors speculate about what their study means, but which their study did not show. Please beware of author speculation. There are only a few who are accurate in their speculations. And some of them win Nobel prizes.
The other article is a blog by a coach who noted that her runners seemed to be having an inordinate amount of calf and Achilles problems. These are clinical and coaching observations and not a published study. But, there truly may be wisdom in systematic observations. Over the past 6 months she noted that this injury seemed to have surged and become a trend. The calf and Achilles problems were often seen among runners who had thought they were purchasing the same shoe they had run in for years only to find that the “heel drop” (heel to forefoot height differential) had dramatically decreased. Initially I was going to post on Coach Jenny’s blog article but I’ll just link to it and make my remarks here. I believe she is right on top of things in her blog.
Over the past 3 years many manufacturers have attempted to “minimize” nearly their entire product line. A shoe which had a 12 mm heel drop, now has 8 mm. And of course zero to 2 mm are often touted as the ideal. But the reality is that not everyone responds well or even the same to changes.
As George Sheehan said “we are all an experiment of one”. And the modern reality is that studies, trends, and memes are aggregate while injuries happen to individuals. And individuals need tailored solutions that are not always the trendy advice making the rounds.
So in spite of some “nay-sayers”, who adamantly disagree, I side with Coach Jenny. Often returning those 4 mm or so back as a heel lift, can make the difference between comfort and pain. Instead of a soft gel or foam heel lift, I prefer a solid heel lift made of firm layered plastic film, hard rubber, or leather. You may find that after months of icing, foam rolling, massage and even lower heel drop shoes, this may be your answer. But if you’ve had the pain that long, you may need to check in with your sports doc. (And hope the advice is different from what has failed during your experiments!)
This is still not the entire answer for many individuals and there are other things to analyze. Shoe changes, training changes, terrain, and recent racing history along with individual biomechanics all come into play for a more complete analysis of the causes and the likely solutions. YMMV
AI has made tremendous strides in the past 15 to 20 years. In going from a constraints and rules based system in which “expert systems” were hailed as the future, to today’s probabilistic and stochastic systems we’ve come a long way. There are many current and future uses for AI and they are far too many to list.
Some recent work has been done in gait simulations in which everything from dinosaurs to people walking with osteoarthritis or cerebral palsy (crouch gait) has been modeled. Strategies have been proposed to lessen the load on the knee using one model. But the strategy was difficult to adapt and I believe only the author of the study was able to successfully and readily use his “intoe” strategy. (Note: Lateral wedging on orthotics has also been found to lessen medial compartment forces in the knee. And that does not need you to study at Monty Python’s Ministry of Silly Walks, to walk like Young Frankenstein or to sing “Walk This Way” while you move about.)
Biorobotics, a new field of robotics, has been used to model a variety of animal methods of locomotion. Snakes, cats, fish, and human like robots have been created for this purpose.
The October 7th edition of Science Magazine features an interesting article which suggested that artificial intelligence products were needed to make connections and correlations for novel ideas on research projects. (Gill, Y et. al. 2014; 346:171-172). This is an excellent idea.
An intelligent system should be at the core of many systems. It should be at the core of all EHR (electronic health records). Some of the advocates, designers, and marketers of these products seem to be first interested in market penetration and are proud of achieving a government defined Level 2 of “meaningful use”. However meaningful use is losing its cachet since it doesn’t add intelligence, thought, or many things that are helpful to a medical record. Insted it adds more data points but not meaning. (ICD 10 coming to a healthcare provider near you next year will also add an incredible amount of not very useful datapoints and has been precicted to cause many physicians to leave private practice.)
AI could be helpful. AI could have assisted by creating a red flag notice on the Electronic Health Record that the patient with a headache and severe stomach pain had just arrived from Liberia. It was entered into the medical record of the hospital but set off no alarms.
Of course the final failure was a human one. The doctors, nurses, and residents should have made connections. It really doesn’t take a computer to put information like that together. The close partner of the patient who brought him to the hospital is said to have informed 3 people that he had come from Liberia, Africa. He did not have a Texas accent. He had more than one classical sign of Ebola or other serious illness. He rated his GI upset at 8/10, he had a fever and a headache and did not have signs that he had a sinus infection as some articles stated.
In this case an intelligent system could have made up for the unwise human conclusions and actions. But there are a few simple lessons:
1) We need to be intelligent and make connections. A diverse knowlege base is helpful. 2) We need to exclude data points that don’t make sense and are suspicious and not likely. 3) We need to have an intelligent core to our EHRs. One in which probabilty and hidden Markov Processes are used will be far better than just using Natural Language Processing (NLP) but it will be harder to implement. 4) The humans are the final arbiters of the decision making process and need to think and understand their own thinking process to produce optimal decision making and to determine the optimal next step in treating their patients.
“The world faces deep problems that challenge traditional methodologies and ideologies. These challenges will require the best brains on our planet. In the modern world, the best brains are a combination of humans and intelligent computers, able to surpass the capabilities of either one alone.” Well stated by Gill (2014).