History of sports nutrition - a 50-year review

FUNCTIONAL SPORTS NUTRITION – JULY/AUG 2017

Research, in part, shapes the way we think, so Ian Craig has taken a historical view of sports nutrition research and how it may have influenced the way we think about the subject today.

Returning home after hosting the IHCAN Functional Sports Nutrition conference in London recently, I must say that I was incredibly inspired with regard to where we are currently moving within the context of working with athletes and active individuals. Granted, I picked the speakers, which would throw in a slight bias, but we had four individuals from very different backgrounds: functional medicine, nutritional therapy, medicine, and performance nutrition. Although their topics were all quite different (depression and gut health; heart rate variability, blood sugar control and macronutrient balance; hormonal regulation in athletes; and science to practice), there were a number of common threads throughout the day.

Most significantly, all four speakers talked about an n = 1 concept, meaning that we need to work individually with each athlete instead of relying on averaged-out statistics from large randomised controlled clinical trials. These carefully constructed research studies are essential for adding theoretical constructs to our understanding of important concepts in sports nutrition, but when it comes down to the level of working with an individual athlete, we need a large tool box of possibilities to choose from.

The early years

To give contrast to where we have come from in sports nutrition thinking, I decided to write a historical review of sports nutrition research for this article. Those of you who have been studying this field for a number of years may remember names such as David Costill, Bengt Saltin and Edward Coyle, who were eminent professors in the 1960s and 70s. They were not specifically nutritionists though; quite notably, and extremely relevant to the way we think about sports nutrition nowadays, these researchers were early exercise physiologists who had a strong interest in muscle physiology.

In Scandinavia, in the 1960s, Bengt Saltin worked with many eminent scientists, including Per-Olof Åstrand, author of Textbook of Work Physiology (4), a book that has guided so many exercise physiology students over the years. Saltin’s early prolific research included titles such as ‘maximal oxygen uptake in athletes’ (5) and ‘muscle glycogen during prolonged severe exercise’ (6). He also became an expert contributor in lactate dynamics and in the understanding of aerobic-anaerobic metabolism. But by the early 1970s, he was starting to publish studies such as ‘diet, muscle glycogen, and endurance performance’ (7) and ‘diet, exercise, and glycogen changes in human muscle fibers’ (8).

If we hop over the Atlantic, early 1970s research studies by David Costill from Ball State University in Indiana, included titles such as ‘muscle glycogen utilization during exhaustive running’ (1) and ‘fluid ingestion during distance running’ (2). Only later in the 1970s, did he study ‘gastric emptying rates for selected athletic drinks’ with Edward Coyle (3).

During the same era, but completely separate from physiology research, at the University of Florida, another prominent figure of early sports nutrition research was Robert Cade. Ironically, he was medically trained with an interest in kidney research and had nothing to do with sports. However, in 1965, he was tasked by the assistant coach for the Florida Gators football team to come up with a solution for the players’ extreme levels of dehydration during their practice and games. This is when the world famous sports drink Gatorade was born. It had an original formulation of: water, salt, lemon juice, sodium citrate, fructose and monopotassium phosphate.

Let’s take a closer look at the types of research that was being done in the 1970s. With a background interest in muscle glycogen, in 1971 Karlsson & Saltin (7) found that the time to complete a 30-km race was improved on average by eight minutes when the subjects increased their pre-race muscle glycogen concentrations by a carbohydrate-loading procedure. Runners who were carb-loaded were able to sustain their optimum pace more easily during the latter part of the race. This research initiated the birth of the carb-loading technique in endurance racing.

Moving into the 1980s, Edward Coyle played a large part in the experimentation of carbohydrate drinks during endurance exercise (9). In 1986, he and colleagues asked seven trained cyclists to ride to exhaustion at 71 per cent of VO2max on two occasions. A glucose polymer solution was given at 20-minute intervals on one occasion and a sweetened placebo drink was given on the other. The plasma levels of glucose remained higher in the glucose polymer trial and cyclists remarkably averaged one hour longer before hitting fatigue (an average of four hours versus three hours for the placebo trial). He repeated a similar kind of study three years later with renowned cycling physiologist Andrew Coggan (10).

According to Marie Dunford, author of Fundamentals of Sport and Exercise Nutrition (11), the early sports nutrition research was all focussed on carbohydrate because it was reasonably easy to study isolated stores of glycogen in endurance athletes via trials on treadmills and stationary bikes. This is in contrast to protein, which has more of a systemic metabolism and is more difficult to study - due to lack of early research, bodybuilders learned more via personal experimentation. Only later on was protein well researched, but in hard-line sports nutrition, exact quantities of protein intake remains very controversial. Overall, this is an interesting observation: certain substrates were studied more than others, not necessarily because of physiological importance, but because of research practicalities.

Turning the century

If we jump forward a couple of decades toward the end of the last century, we find figures such as: University of Aberdeen researcher Ron Maughan, now head of the Australian Institute of Sport Nutrition Louise Burke, and even the controversial independent authority Michal Colgan. Maughan came to sports nutrition with a base of exercise biochemistry, Burke was a dietician and Colgan was a performance nutritionist. Mirroring mainstream dietetics, the majority of sports nutrition research focus had been on quantifying macronutrient requirements for athletes, unfortunately with no obvious recognition of quality. The American College of Sports Medicine, American Dietetic Association and Dieticians of Canada joint position statement on nutrition and athletic performance (12) from year 2000, in Table 1, demonstrates this ideology nicely:

Table 1 - ACSM Position Statement (12)



The philosophy at the time was that an athlete (like a lay person) could get all their nutrient requirements from a ‘good balanced diet’, whatever that might mean… If you take a look at the 2016 ACSM position statement (13), unfortunately not much has changed. The range of figures for macronutrients has increased slightly (allowing for increased practitioner interpretation) and vitamin D, antioxidants and fish oils have been added to iron and calcium as potential supplemental inclusions in an athlete’s regime. Nowhere in the 25 page manuscript, does it mention anything about ‘organic’ or ‘grass-fed’ or ‘food sensitivities’, etc. and I’m still waiting for mention of the numerous other essential vitamins and minerals - do they need to prove ergogenic potential before being included in such a document? Many sports nutritionists are unfortunately still filling their athletes with refined wheat-based cereals and low-fat dairy, sandwiches and pasta dishes, all in the name of macronutrient quantity.

Michael Colgan was a bit of an outlier during this era though - in the early 90s, he was advocating a very strategic use of vitamin, mineral and amino acid supplements - more in line with the body building self-experimentation at the time. Given his unique voice in sports nutrition, he built his own institute and was not part of an existing academic establishment. I read his first book Optimum Sports Nutrition (14) in the late 90s and having previously been quite disillusioned by prevailing sports nutrition guidelines, I followed a lot of his advice in my own pursuit of athlete excellence. I found that, controversial as he was, he offered a fresh and contrasting approach to the paradigm of the time.

Thankfully, though, the new century brought some fresh blood into this research arena and the number of labs around the world with a dedicated sports nutrition focus has blossomed. The basis of most labs is still physiology or biochemistry, but more diverse subjects are being tackled. For example, within a year of one another, Alan Goldfarb (15) and Graeme Close (16) published evidence that vitamin C can either hinder or aid recovery from strenuous exercise, seemingly dependent on the particular research trial. What ensued was 10 years of conflicting research on antioxidants, a topic that we will hopefully review in these pages later this year.

Then in 2009, something very exciting happened: research in Andy Jones’s lab at the University of Exeter revealed that subjects who consumed half a litre of beetroot juice per day for six days (compared to a control of blackcurrant cordial), cycled 16 per cent longer in a time to exhaustion trial (17). At last, somebody was looking at real foods and not just powdered solutions. Since the time of that research, the flood gates have literally opened on enquiry into natural foods within the world of sports nutrition. For example, in a recent webinar that I gave on sports drinks, I shared research on cherry juice (18), sugarcane juice (19), a honey drink (20), cashew apple juice (21), acai berry juice (22), date syrup juice (23), and watermelon juice (24).

The views on supplementation in sports nutrition have also changed since the beginning of the century. I watched Louise Burke present at the Sports Science Institute in Cape Town around 2010 and she told the audience that despite the Australian Institute of Sport (AIS) originally having a recommendation of no supplementation, athletes would be going out and buying products themselves. The AIS therefore changed their practice to actually recommending certain types of supplements that are deemed safer to take than others. This change in guidelines has been shadowed by the English Institute of Sport and the Informed-Sport testing of supplements has also changed this landscape hugely during the past few years.

The future of sports nutrition

So we’re in a really exciting era in sports nutrition - lots of varying research studies and more open thinking. However, I do feel the need to comment on research methods; in sports nutrition research, we are still a bit stuck on the classic randomised, placebo-controlled trials type of enquiry, which really only compares two variables to each other. If we return to the last century for a moment, as a student I assisted with a Physical Therapy section at the 1996 American College of Sports Medicine annual conference. Unlike other sections of the conference, instead of listing research trials one after another, each speaker actually presented an extremely detailed case study, after which time the case would be discussed amongst the audience. There was no right or wrong answer in these discussions, but members of the audience would leave the conference armed with a number of new ideas to try out with their difficult rehab cases.

Perhaps we would benefit (in part) from such a platform of education delivery in sports nutrition - that way we wouldn’t become so ‘stuck’ on paradigms and principles while we wait for the next research study to come out and point us in a new direction.

Referring back to Fundamentals of Sport and Exercise Nutrition by Marie Dunford (11), she talks about the growing scientific area of nutrigenomics, within which we can personalise the approach that we take with an athlete’s nutrition, along with their training and recovery strategies. If we need scientific ‘proof’ for an individualised approach, this may be it.

We can go further than simply recognising individualisation in sports nutrition though. By adopting approaches of functional and integrative medicine in sports, as shown by the recent IHCAN conference, we can become very sophisticated in the way that we deal with an athlete’s gastrointestinal health, immunity, musculoskeletal integrity, endocrine and nervous systems, and their neurotransmitter balance. Additionally, we can even go a layer deeper in our dealings with athletes and dip into agricultural studies of food quality. After all, we don’t want to put diesel fuel into our athlete’s finely tuned petrol engine…


References

  1. Costill D et al (1971). Muscle glycogen utilization during exhaustive running. J Appl Physiol. 31(3):353-356.
  2. Costill D et al (1970). Fluid ingestion during distance running. Arch Environ Health. 21(4):520-525.
  3. Coyle E, Costill D et al (1978). Gastric emptying rates for selected athletic drinks. Res Q. 49(2):119-124.
  4. Åstrand PO & Rodahl K (1978). Textbook of work physiology: physiological bases of exercise. McGraw-Hill.
  5. Saltin B & Astrand PO (1967). Maximal oxygen uptake in athletes. J Appl Physiol. 23(3):353-358.
  6. Hermansen L et al (1967). Muscle glycogen during prolonged severe exercise. Acta Physiol Scand. 71(2):129-139.
  7. Karlsson J & Saltin B (1971). Diet, muscle glycogen, and endurance performance. J Appl Physiol. 31(2):203-206.
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  9. Coyle E et al (1986). Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. J Appl Physiol. 61:165-172.
  10. Coggan A & Coyle E (1989). Metabolism and performance following carbohydrate ingestion late in exercise. Med Sci Sports Exer. 21:59.
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  12. American College of Sports Medicine, American Dietetic Association and Dieticians of Canada (2000). Joint Position Statement – Nutrition and Athletic Performance. Med Sci Sports Exerc. 32(12):2130-2145
  13. American College of Sports Medicine, Academy of Nutrition and Dietetics & Dieticians of Canada (2016). Nutrition and athletic performance - Joint Position Statement. Med Sci Sports Exerc. 48(3):543-568.
  14. Colgan M (1993). Optimum Sports Nutrition. Advanced Research Press.
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  16. Close G et al (2005). Ascorbic acid supplementation does not attenuate post-exercise muscle soreness following muscle-damaging exercise but may delay the recovery process. Brit J Nutr. 95:976–981.
  17. Bailey S et al (2009). Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol. 107(4):1144-1155.
  18. Bowtell J et al (2011). Montmorency cherry juice reduces muscle damage caused by intensive strength exercise. Med Sci Sports Exerc. 43(8):1544-1551.
  19. Kalpana K et al (2013). The effects of ingestion of sugarcane juice and commercial sports drinks on cycling performance of athletes in comparison to plain water. Asian J Sports Med. 4(3):181-189.
  20. Ahmad N et al (2015). Effects of Post-Exercise Honey Drink Ingestion on Blood Glucose and Subsequent Running Performance in the Heat. Asian J Sports Med. 6(3):e24044.
  21. Prasertsri P et al (2013). Cashew apple juice supplementation enhanced fat utilization during high-intensity exercise in trained and untrained men. JISSN. 10:13.
  22. Sadowska-Krępa E et al (2015). Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid pro le in junior hurdlers. A pilot study. Biol Sport. 32:161-168.
  23. Anand T et al (2014). Development of bacoside enriched date syrup juice and its evaluation for physical endurance. J Food Sci Technol. 51(12):4026-4032.
  24. Shanely R et al (2016). Comparison of watermelon and carbohydrate beverage on exercise-induced alterations in systemic inflammation, immune dysfunction, and plasma antioxidant capacity. Nutrients. 8:518.