Human Limits

Exploring performance and health with Michael J. Joyner, M.D.

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Archive for July, 2013

Top This Gary Player!


I have devoted a couple of posts to 77 year old golf legend Gary Player and his lifelong devotion to fitness.   In response to my most recent post a reader sent the video clip below about 86 year old gymnast Johanna Quass.  I have been thinking about exercise and aging for a long time, but the clip below is among the most remarkable things I have ever seen.   Clearly a lifetime of training, talent, and injury avoidance are required to make a performance like that happen.  However, nothing like it happens without staying with it.


click here for video


I have been doing more body weight calisthenics and strength training over the last year, but this video has me thinking maybe I should take a tumbling class or start jumping rope again like I did in high school to improve my footwork for basketball.  In the end, loss of strength and balance leads many older people to become frail and lose their independence, maybe we need to rethink what we tell middle aged people to literally keep them independent and off the floor.


Outside Magazine Article


Screen Shot 2013-07-27 at 8.57.41 AM


click for full article


Healthy After 65

Today’s post is a short one and focuses on a new CDC report on healthy life expectancy (HLE) at age 65.  This differs from total life expectancy (LE) and is a measure of how long the average person can expect to life in reasonably good health after they hit 65.  It is important because data like this can help individuals, families, governments, and other organizations think about health and other services that older people will need over time.   The figure below shows estimates based on 2007-2009 data.   For those who want to take a deeper dive, the report is full of all sorts of information on the effects of sex, state, and race on healthy life expectancy.   In general women do better than men; there is substantial regional variation with issues in the South especially and blacks do worse than whites.


Here is the bottom line from the CDC report:

“For the total population at age 65 years, HLE was lowest among southern states. For all persons at age 65 years, the highest HLE was observed in Hawaii (16.2 years) and the lowest was in Mississippi (10.8 years). During 2007–2009, HLE as a percentage of LE for persons at age 65 years for the total U.S. population ranged from a low of 61.5% in Mississippi to a high of 78.2% in Vermont (Table). Conversely, the number of remaining years in fair or poor health for persons aged 65 years was 6.7 out of 17.5 years of LE for those living in Mississippi and 4.2 years out of 19.4 years for those living in Vermont.”


My bottom line is that this regional and other differences noted in the report are not going to be solved by medical care alone and that some areas of the country need aggressive public health interventions to catch up.  These topics have been covered many times in earlier posts on life expectancy.





Post Tour Doping Thoughts

The Tour de France ended yesterday and I wanted to use it to continue to highlight issues related to sports doping.   Since the tour started, there were a number of busts in the track and field world apparently related to the use of a banned stimulant by Tyson Gay and several sprinters from Jamaica. Ultimately athletes are responsible for what goes into their mouths or bodies via other routes, but adulteration of “supplements” with banned substances is both a real problem and a convenient excuse.


1% is a Big Deal

The other issue I want to bring up is that a 1% edge in something like a 10,000m run would be a huge margin of victory (100m) or a huge improvement (~16-17 seconds for a world class runner).  If you simply translate this to the Tour de France which lasts about 80-90 hours it would be about 50 minutes.  That is unrealistic due to the team tactics and the fact that every day is not a test for the top riders.  However, this year there were more climbs than normal and perhaps 8 or 10 hours that might have been decisive, so 1% would be a 5-6 minute margin.   If you believe that drug tests and the biological passport are beatable with low dose drugs, a doping regimen that generates a 1% edge while remaining undetectable seems conceivable to me.   Lance Armstrong and his collaborators showed what is possible when the East German approach was privatized and there is more than enough at stake with a Tour win to tempt people to learn to fly under the doping control radar.


Show the Data

My colleague Ross Tucker, one of the World’s leading experts on human performance, has called for more transparency related to publishing the power outputs of riders during the Tour and other races.  I support this call completely.  He also has thoughts about the progression of performances that I agree with and recently posted on related to distance running.  Finally, here is a deep dive by Ross on this topic that is worth the read.



The biological passport may be working to limit doping in endurance sports.  The physiological data, especially in cycling where it is possible to measure power output accurately, should be of great interest to those trying to ensure clean competition.  Show us the data.


“The Sports Gene”: A Book Review

Over the last 10 or 20 years authors like Malcolm Gladwell and Jared Diamond have had multiple bestsellers on topics related to social science and anthropology among other things.  This is encouraging to me as a scientist and shows that the public appetite for information about science is high.  Now comes “the Sports Gene” by David Epstein of Sports Illustrated. The Sports Gene explores the nature versus nurture argument in the context of world class athletic performance.  It does an excellent job covering the scientific basis of athletic performance and amplifies the research with an impressive collection of narrative examples and interviews.


Pop science books are frequently criticized by “experts” as being oversimplified “Readers Digest” versions of the scientific landscape based on cherry picked data that is then distilled into a compelling story with little mention of the limitations of the data or alternate explanations. These oversimplified ideas then become part of the conventional wisdom.  Perhaps the best recent example is the so-called 10,000 hour rule about what it takes to become expert (or even world class) at any given activity. Epstein shows just how caveat filled the 10,000 hour concept is and points out that it only works if you have sufficient talent to begin with and that what might be called trainability varies remarkably from person to person.


So what is talent?   Major league baseball players struggle to hit the softball pitcher Jenny Finch showing us just how specific hand eye coordination, vision, practice, anticipation, and reading the opponent is.  How they interact to make a great hitter is even more complex.    The discussion of this topic reminded me of how Henry Aaron sat on the bench peering through a hole in the top of his cap to generate a mental map of any biomechanical clues about what the pitchers were throwing.   A similarly thoughtful discussion of the big “size sort” of body sizes to the right sport over the last 30 or 40 years is especially insightful and entertaining.  This is a topic I posted on last year during the Olympics and it explains all sorts of things, but curiously little is known about the genetics of height or just about any other trait that seems so essential to athletic performance.  When there are genetic clues, they are typically very complex and the effect size of the genes of interest is small. There are also excellent sections on the Jamaican sprinters and Kenyan runners as well as sudden death in young athletes to highlight just a few of the topics covered.


So should you read this book? I recommend this book generally to sports fans, but more importantly this book should also be read by people who are broadly interested how an individual’s biology interacts with their behavior (training), their environment, and their culture.  Those who think that our genes are our destiny may want to think again.   Those who think it is only about 10,000 hours will want to think again too.  There are also many parallels between the biological and other factors that determine athletic performance and things like our individual health and also population health.  In most cases there is some ill-defined biological pre-disposition that only finds full expression when everything is just right or perhaps wrong in the case of disease.


This book might also be of interest to proverbial Little League parents interested in what sports their children might excel in. The limits of early overspecialization are discussed and in some sports like women’s gymnastics early specialization appears to be critical because there is a limited age related sweet spot.  For other sports, perhaps overspecialization is a bad thing and maybe we need go to go back to the future with traditional physical education.  This approach would develop a wide variety of more generic athletic and physical fitness skills that could be mixed and matched later as the interests of the aspiring athlete emerges.  If I have one criticism of the book it is that it could benefit from a few pictures or perhaps some graphs. However this is a minor concern and no way limits my enthusiasm for the Sports Gene.  That having been said, below is a picture of Michael Phelps, Ian Thorpe and Alexander Popov who have 40 Olympic medals in swimming between them.




These men are all about the same size, and the picture suggests that perhaps there is an optimal size for swimming.  But of course they also trained hard and perfected their technique more than amplifying whatever talent they started with.  Was it their talent (nature) that got them to the top or their training, skill, and environment (nurture) that got them there?   Read the Sports Gene and decide for yourself.


The World vs. Kenya!

East Africans dominate middle and long distance running and last year during the Olympics I did several posts on them.  Recently, there was a remarkable paper published documenting very high levels of physical activity and VO2 max values in “untrained” Kenyan school children.  The tables below tell the story.  The Kenyan kids were small traveled on foot an average of 7.5 km to school and did an hour or more of vigorous physical activity per day.  Some of these very high values are due to the fact that these kids are so small.  It is complex but VO2 is scaled to body size and when the scaled values (expressed as body weight to the 0.75 power) in the second table are converted for say a 60kg 14 year old, a value of 65/ml/kg/min would be physiologically similar.







This Data & International Competition

A superficial look at this data suggests that perhaps the rest of the world should just quit trying to do well at distance running, but there is another way to look at the data.  For example is there enough “aerobic talent” in the U.S. to compete with the Kenyans?  To look for an answer to that question I went to a database of Minnesota high school track times and found that in 2013 almost 50 boys had broken 4:30 for the 1600m run which is about 10m less than a mile.  Minnesota has a population of just over 5 million and the U.S. has a population of `310 million.   So if you extrapolate the Minnesota numbers to the entire country it seems reasonable to suggest that perhaps about 3,000 high school boys per year can run a 4:30 mile.  How many of these kids were well trained, how many ran year round, and more importantly how many might improve dramatically if they continued for a few years with good coaching?  A generation of runners is lasts perhaps 4-8 years so that means there are between  12-24,000 people in a given generation of potential US runners with at least some ability and this does not count the people that are either doing other sports or doing nothing.  Anyone who has been around distance running for a while knows a 4:30 miler who went on to great things.  Below is a quote from Frank Shorter related to John Parker’s novel on distance running “Once a Runner”.


…….a quote by Frank Shorter, from a conversation he had with the author during one of their training runs (they were roommates and friends): “How did I know you ran the mile in 4:30 in high school? That’s easy. Everyone ran the mile in 4:30 in high school.”…….


Does Matthew Elliott Prove My Point?

Recently, a miler named Matthew Elliott emerged onto the world scene.  He is a 27 year old school teacher who ran 4:42 for the mile in high school.  Elliott went to a small college with a cross country but no track team:


“At Presbyterian College in Clinton, South Carolina, Elliott ran cross country, but there was no track team. He used his final year of eligibility while going for his masters in early childhood education at Winthrop in Rock Hill, where he ran indoor and outdoor track, “and that’s where I found that I had a little bit of talent,” he says. He qualified for the NCAA Championships in 2008 but did not make the 1500-meter final.  Still, that was enough for him to keep running beyond college.”


Elliott found a coach and continued to improve and is now in a position to potentially represent the U.S. in the World Championships.   Elliott also works full time as a teacher of young children with special needs.



When you look at my talent pool estimate above, read about Matthew Elliott, and talk to longtime observers of distance running and hear the many stories of wasted natural ability about the kid who “ran 4:15 with no training”; one conclusion is that there is more than enough talent in the U.S. to compete with the Kenyans and Ethiopians.  When you consider what the rest of the world has to offer it is hard to believe that there is not enough talent out there, if identified and cultivated, to give them a run for the money.



Wheat Belly & Low Carb Diets

A colleague who wants to lose some weight sent me an e-mail asking about the “Wheat Belly” diet which advocates cutting wheat based products and foods from your diet.  A book based on this concept is a best seller and among other things there is discussion in the book about how “addictive” wheat based products are and some potentially bad biological effects of high yield varieties that have emerged through selective breeding over the last 50-100 years.  From what I can tell, this is just the latest iteration of the “low carb” approach to weight loss and dieting that has had a number of incarnations over the last 50 or more years.  So, what did I tell my friend?


1)  Low Carb Diets Reduce Variety

There is pretty good evidence that just restricting food variety reduces the amount we eat.  Get rid of wheat based products and you restrict variety a lot.   Here is a link to an animal study that makes this point:


“Thus, the present results suggest that limiting dietary variety, regardless of palatability, may be a useful strategy for weight loss in overweight and obese individuals by reducing caloric intake within individual meals.”


2)  Carbohydrate Restriction & “Water Weight”

The pictures below are two photos taken a few days apart of Olympic 1500m swim champion Grant Hackett.  On the left is a shot when he was tapered and after he had carbo loaded for a 10k open water swim (the swimming equivalent of a 26 mile marathon).  The photo on the right is a few days later when he was back to his normal training.  Along similar lines, it has been known for years that low carb diets lead to rapid weight loss because water is stored along with carbohydrate in the body.  When the carbs are depleted the water goes with them.   A study from the 1990s tracked this carefully over a few days of a very low calorie diet and showed a 4.3 kg (9 lb) weight loss almost entirely from changes in body water.  A lot of the appeal of low-carb diets is this early and impressive weight loss.  Don’t be fooled into thinking it is fat loss.



3)  Feeling Full Helps

Dietary fat and protein probably make most people feel full for longer.  The biology is complex and relates to how fast food leaves various parts of your digestive tract and a whole bunch of hormonal signals related to what makes us hungry and what makes us feel full.   So, this is perhaps another reason that low carb diets seem to work.   However, there is concern that low carb but high fat and protein diets work but are not optimal to reduce or control things like cholesterol.  This too is a complex topic with a lot of individual variability.  But feeling full for longer is good if you want to lose weight.


4)  The Brain & Food Addiction

The way the brains of people who are obese or prone to overeat are stimulated by food or images of food is different.  Does this mean they have a food addiction?  Who knows, but the summary below does give us some hints about what the issues are and what might be done to address them.


“Prefrontal cortex areas linked to cognitive evaluation processes, such as evaluation of rewarding stimuli, as well as explicit memory regions, appear most consistently activated in response to images of food in those who are obese. Conversely, a reduced activation in brain regions associated with cognitive control and interoceptive awareness of sensations in the body might indicate a weakened control system, combined with hypo-sensitivity to satiety and discomfort signals after eating in those who are prone to overeat.”


Is this innate?  Or does it happen over time.  Is it biology or environment?  My guess is that is probably both and that the brain can be rewired over time and with some effort.  Self-control related to both diet and exercise seems to be the key for long term successful “losers”:


“These findings suggest that weight loss maintenance efforts can be improved by addressing challenges such as long-term self-monitoring and problem-solving skills, and that maintenance success might depend on how people think as much as what they do.”


What is interesting is that both the brain imaging studies and the behavioral studies both cite issues related to body perceptions and self-monitoring.  Perhaps it is more than just will power and there is a “skill” and focus element to weight loss like most other things that are difficult to do.


5)  Exercise & Physical Activity

Most of us don’t have the time, energy or motivation to train like an elite athlete and be a in a position to essentially eat all day long.   However, there is some evidence that if we exercise a lot we might sit around more during the rest of the day and lose some of both the energy expenditure benefits and health benefits of exercising.   So a key thing to remember is to both exercise and also build more low grade physical activity into your day.



Despite wave after wave of claims related to low carb diets, at some level if you have seen one you have seen them all.  They clearly “work” at generating rapid weight loss, reducing dietary choice and they probably help people feel a bit fuller.  However, the key to successful long term weight loss appears to be related to developing the skills and behavioral strategies needed to effect long term changes in diet, exercise and overall physical activity.   What is interesting about my colleague is that he is highly successful, self-disciplined, and focused in many areas of his life.  He is also seen as a problem solver by many co-workers.  So, he has the general skill set needed to be a successful “loser”, and my bet is that he will be once he consistently applies these skills to his exercise and weight loss goals.


Never Enough of Gary Player

A couple of months ago I highlighted Gary Player’s fitness regimen.  At age 77 he is in the ESPN “body” issue.  Here is a link to article on him and the video clip below show the great man in action.

click here for video