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On March 16th I had the occasion to interview Dr. Trent Stellingwerff about nutrition and hydration related to exercise performance it proved to be a popular read. In the interview below, we discuss genes and how they may or may not influence training and racing performance for East Africans and European and North American-based athletes.
Stellingwerff is a former track and field athlete who competed in the NCAA for Cornell University, where he was selected as co-captain. He also competed in the CIS for the University of Guelph, where he twice earned All-Canadian status.
Stellingwerff was an academically decorated student who made the Dean’s list at Cornell University and was twice awarded Academic All-Canadian status during the years 2001 and 2002. In 2006 he took a position in Switzerland for the Nestle Research Centre (Powerbar) as a Senior Research Scientist in Sport Nutrition, Energy and Performance. Stellingwerff has also served as the Nutrition and Physiology Consultant for Athletics Canada.
He and his wife Hilary (International-level 1500m runner), recently relocated to Victoria, BC where he accepted the position of Senior Physiologist working with the Canadian Sport Centre Pacific.
Christopher Kelsall: From a physiologist’s perspective, what do you make of the recent marathon performances from the Kenyan men? Many of them young and racing their first marathon.
Trent Stellingwerff: Certainly there has been an absolute explosion of marathon performances – I mean, Kenya is going to have to leave a sub-2:05 marathon guy at home this year for London! However, I’m not sure if my answer will have to do with physiology and training or more to do with socio-economical circumstances causing this marathon explosion.
First, exercise physiologist have been searching for several years for reasons why athletes from the East African Region (Kenya, Ethiopia, Eritrea, Uganda) are so successful in distance running. Now, I don’t want to devalue my chosen profession, but frankly, over five-plus studies, there really hasn’t been any super strong physiological or genetic explanation(s) for their superiority. No real differences in elite Kenyan vs. European-based athletes with the same training volume, VO2max etc. There are some suggestions that their small lower legs (calves) result in better running economy. However, this is not a strong enough explanation to explain the incredible depth in marathon performances coming out of Kenya. Further, there are some theories on altered growth and development when being born at altitude, but are lacking strong scientific data to confirm these theories. Finally, training wise, there has also been a shift towards much more specific marathon coaching and periodization, rather than just 10,000m runners who do a weekly longer run for a while and try and race a marathon.
Economic and Environmental factors
But, I think the recent huge draw to the marathon is the massive paydays associated with marathons as compared to track racing. A young Kenyan can go run a sub-13 minute 5000m on the track and get 1000 euros for 8th place. Or, this young talent can try and load-up and win, or place, at one of the many global marathons and earn more than $50,000 to $100,000. This explosion of marathon talent out of Africa may be more a matter of economics than physiology or genetics.
Further, like hockey in Canada, or basketball in inner-city America, or football (soccer) in Brazil, running is “the” sport in East Africa, and their ticket out of poverty. Belief and passion are hugely impactful performance variables that physiologists cannot measure!
CK: To be clear, you are saying that research indicates that the Kenyan genetic variables are no different than what exists in European-based people?
TS: That is correct – when trying to find whether genes are predictive of Kenyan marathon or Jamaican sprint performance, nothing “yet” can be found. Now, looking for a combination of genes to explain a physiological or phenotypic outcome is like looking for a needle in the haystack, so perhaps in the future scientists will figure something out that is more predictive and concrete. Dr. Yannis Pitsiladis out of Scotland has done most of this research, and describes this in a recent interview here: Genes Cant Explain Why Usain Bolt Runs Fast And You Don’t where he says, “To date there is zero predictive capacity in sports genetics,” Pitsiladis says. “So the stopwatch is a far better predictor than all the genetics to date.” The article doesn’t say that genes are unimportant, just that the variants that science has so far associated with things such as power and ability to improve aerobic endurance don’t explain actual performance particularly well, at least not in runners studied by Pitsiladis. There may be many more variants to be identified, but there are also likely very strong non-genetic influences on performance.
CK: So North Americans and Europeans have no valid physiological excuses (as far as we know).
TS: Given what we currently understand, which might change with more research, I would say that they have no genetic excuse. As far as physiological excuses, this is much more complex, as this is a combination and depending upon genetics, type of training, training adaptability, environmental, psychology (which can impact physiology), nutritional (which can impact physiology) and even body type / anthropometric characteristics.
Certainly, on average, African distance runners have a very low BMI (body mass index) compared to the average N. American. Being 5’5” tall and 120 pounds is certainly going to help with heat dissipation, fuel (carbs) and fluid per kg body weight and load mechanics when running the marathon compared to the typical heavier N. American. But, certainly, the very non-African Eric Gillis’s and Bruce Deacon’s of the world are also very small guys. As I said above, there also may be some very strong environmental factors (e.g. being born and raised at altitude) that may drive early physiological adaptation that have not yet accounted for. E.g. I do find it interesting that Ryan Hall was born and raised in Big Bear, CA – which is about 7,000 to 8,000ft (~2200 to 2300m) above sea-level, which is nearly the same as the 2400m of Iten, Kenya.
CK: Now that these younger athletes are bypassing what used to be part of what was a traditional progression from the 5,000m and 10,000m distances, do you think we are going to miss a generation of 26-low 10,000m runners?
TS: Good point. I have not thought of it this way. But, given that the world-junior record holder (the late Sammy Wanjiru) ran 26:41 for 10,000m as an 18-year-old and then going straight to the marathon certainly supports this statement. Athletes are probably looking and assessing (with their agents) and balancing: can I place top-three in 10 to 15 5,000m and 10,000m world-class track races or can I place top-three in one or two marathons? Which will earn me more fame and more money per year?
CK: Some Kenyans have said that their dominance is not genetic, but partly attitude and altitude (environmental). In Canada until very recently the Athletics Canada A+ standard (for men) of 2:11:29 seemed ridiculously hard, yet three have qualified and we know Bairu will hit it one day. Are the Kenyan’s correct? Is it a more of a mental and environmental thing (than we realize) that separates them from the rest of the world?
TS: Yes – I completely agree. We Canadians have lots of elite genetically gifted muscle and hearts and lungs in any event/sport in Canada. We just need the right individual to 100% commit their lives to a certain sport passion, with successful coaches and modern sport-science support, and the right environments, and I do believe that we can compete with any country in the world! Five years ago who would’ve predicted that we would have three male marathoners and probably (TBD) three female hurdlers at the Olympics? I bet no one.
I’m an analytical guy, who works with all of our marathon runners, and I can tell you that Reid Coolsaet, Eric Gillis, and most recently Dylan Wykes did NOT run their current marathon bests in ideal weather conditions. All of those races were super windy. A lot of things need to line up. But from a physiological, genetic and training perspective, I think all three of those guys (along with Simon Bairu) can break 2:10, if not several minutes quicker, at the very least (I’ve done the modelling and calculated wind drag and different fades due to the wind alone). Again, lack of injuries and good weather and pacing need to line up, but it is completely feasible and believable.
What is interesting, is all of these guys have immersed themselves into world-class training environments, where the cream rises to the top. They all run many weeks above 200kms-per-week with quality, but also world-class recovery, sport-science in there as well!
CK: The so-called “quality” within a 200 kilometre-plus week, would that be no more than at their Anaerobic Threshold? With only introducing anything much faster within a couple months of the taper?
TS: In terms of total training intensity distribution, to effectively handle 200+km/week at least 75% per week of training needs to be below aerobic threshold (<2 mmol/L lactate) – so the athlete is tired from the massive volumes of training, and less so from the intensity. In more developing athletes, maybe 80 to 85% of work would be below aerobic threshold. Some recent research, and good anecdotal feedback from different coaches I work with, has also shown good value in a polarized training approach, with a lot of neuromuscular work (e.g. some explosive plyometrics, short hill sprints and high-intensity training, all with good amounts of rest) and only periodic (only once or twice-per-week at the most) anaerobic threshold training (running right at 4mmol/L) – even in marathon runners. Of course, in marathon-specific prep, a good program will include ever-increasing levels of marathon specific pace work, and periodically reaching down to anaerobic threshold.
CK: What does world-class recovery look like, is it more active than laying about in the savannah in a hammock?
TS: Being able to really “switch off” is incredibly important, which might include the hammock (but usually involves time away from computers, TV’s and smart phones ;)) But, by world-class recovery, I am talking about the combination of nutrition, hydro and compression therapy, sleep, massage, chiro and proactive physiotherapy. From a planning/periodization sense, I also mean planned and periodized down periods, and times in which training load is much lower, which allows for consolidation of training gains. When you are an elite athlete, striving for international success, it actually takes trust and confidence in your training program to take some planned ‘down-time’ or a programmed ‘recovery’ week, instead of constantly burning the training candle and pushing for more. But, without these important periods, year-to-year performance increases tend to be less due to training staleness and injury risk.
CK: Who are your coaching mentors?
TS: I have had the opportunity to be coached by many folks throughout my personal running career. Perhaps, for me as an athlete, having so many different coaches wasn’t ideal. But, now as a physiologist/coach, I view this as an asset as I can learn and can take the pros and cons from each person I have worked with over the years to define my own training philosophy.
As a young club athlete, I learned a lot from our Sarnia Club Coach Vito Delben, who coached sub-4 minute miler Harvey Mitro, as well as Jay Cantin (3:42 1500m out of high school). He really taught us to be warriors and psychologically strong. At Cornell University, I had several coaches: Lou Deusing and Jerry Smith. Jerry is now getting a bunch of attention on Letsrun.com as he is currently coaching ultra-endurance runner Max King and known for his incredibly tough workouts. Finally, for my five years at Guelph, and until now, I have learned so much from Dave Scott-Thomas (who was also my NCCP instructor), who I know learned a lot from Victoria coaching gurus when he was here during his master’s of coaching (e.g. Ron Bowker, Wynn Gmitroski and Brent Fougner). I would bet that Dave and I exchange three or four emails-per-week, constantly bouncing ideas off each other, and trying to push our respective skill-sets and knowledge forward.
Academically, I have learned much for reading the likes of Lydiard, Bowerman, Dellinger, Daniels, Coe etc., and more recently, research out of Norway on polarization of training in endurance sports (by Seiler). Over the years, there has been great training studies and adaptation research coming out of Copenhagen (e.g. Prof. Bengt Saltin), Sweden (Prof. Hultman and Bergstrom), Maastricht University, Australia and right here in Canada at the Universities of Guelph (e.g. Prof. Spriet & Graham) and McMaster University (Prof. Phillips, Tarnopolsky and Gibala), as examples.
CK: Is this [polarized training] about training controls via heart rate at and around lactate threshold around a sound program?
TS: Polarized training (I somewhat explained this above) is the approach of doing a lot of work aerobically (very large volumes of lower-intensity training), a fair amount in the high-intensity (but short) neuromuscular firing domain, and then only periodically doing pure lactate threshold training (e.g. threshold runs once-per-week most of the year, and then during specific prep, maybe twice-per-week). There is a great free-access review on this topic by Dr. Seiler for download here.
Too much lactate threshold training can be too physiologically demanding and very hard on the sympathetic nervous system. It can get results in the short-term, but too much training in the lactate domain has somewhat limited long-term returns. Some coaches don’t recognize that lactate tolerance is trained quickly and maxed-out quickly (like only 4 to 8 lactate specific workouts, depending on the athlete). When you break down a unit of glycogen to lactate via glycolysis an athlete produces only three energy units (3 ATP). But, training to enhance the aerobic system (e.g. increasing mitochondria and muscle capillarization) takes decades to develop, and actually results in not even producing lactate and producing a lot more energy per unit of carbohydrate broken down (36 ATP!). Would you rather go three miles to the gallon and produce a lot of lactate or 36 miles to the gallon and produce minimal lactate? Given this, and the fact that the 1500m is still 75% aerobic in nature, it should not be surprising that many world-class milers run more than 100+ miles-per-week.
CK: We learned this in the late 1950s. What is new in “polarized training” that we don’t already know from Arthur Lydiard’s block periodization training?
TS: Indeed, we need to be careful about not describing older theories and findings with new grandiose words, as a lot of the ground work and basics of training (and science) knowledge have been laid down many years ago now.
I would suggest the big difference between what we now understand versus Lydiard’s time is more hard evidence to support many of the concepts that Lydiard, and others, put forth. There is a big difference between having coaching anecdotal evidence that something might work (e.g. as Lydiard did over many, many years testing on himself and his athletes) vs. doing several very well controlled and measured studies to truly validate a concept (e.g. as Seiler and others have done with carefully examining and validating polarized training models). Don’t get me wrong, I believe coach intuition and the coaches ability to trial and error many new ideas/concepts is usually the best starting point for any applied sport scientist. But, to truly validate something, it needs to be done in a properly controlled study environment.
Further, I would suggest that nearly every successful distance training program is loosely based on many of the training principles put forward by Lydiard some 50 years ago. However, I would also suggest that if modern runners were coached on pure Lydiard block periodization, they wouldn’t run as fast as they could with a modern training program that has an underlying Lydiard type fundamentals. Instead of pure Lydiard block periodization, many successful modern coaches probably take a more complex training approach, with many different training systems being touched throughout a given period, but the emphasis of each training system/component being focused upon at different times of the year.
We need to give respect to Lydiard’s monumental contributions to endurance training periodization, but also appreciate that modern training has evolved from many of those basic principles, and will continue to evolve as we learn more and more. For example, I have been doing a lot more thinking and reading into how fatigue and recovery profiles differ drastically between a pure endurance workout (recovery time 24 to 30hrs) compared to pure high-frequency neuromuscular fatigue type workout (e.g. pure speed, which might take 3 to 5 days to recover from, and Charlie Francis even suggested world-class sprinters might take seven to nine days to recover from). We have a huge deficit of knowledge around neuromuscular adaptation and fatigue profiles, and I’m sure of the next few years, we will learn more about this as well, which will evolve training philosophies once again.