sports nutrition information

In 1990 Andrew Hamilton was primarily engaged in fitness teaching. The following year, his growing interest in optimum nutrition led him to embark on a chemistry degree course at Aberdeen University, from which he graduated with first class honours. Andrew then returned to the fitness industry as writer and researcher, although he continues to teach fitness to a few selected clients. In 2000 he became accredited to teach and assess the new national NVQ qualification in exercise and gym and three years later gained the American College of Sports Medicine’s qualification in exercise testing, prescription and personal training.

By anybody’s standards, 1990 was an eventful year: Saddam Hussein invaded Kuwait, Margaret Thatcher resigned from office, the Berlin Wall finally fell and middle England revolted against the poll tax. On the football field, Germany beat Italy 1-0 in the World Cup final; on the track, Linford Christie won the 100m gold in the Commonwealth Games and European Championships, while Colin Jackson repeated the same double in the 100m hurdles. Oh, andPeak Performance was launched!

It wasn’t just the worlds of politics and sport that looked very different from today. Flick through the early issues of PP and it soon becomes apparent that our perspective on sports nutrition has also changed fundamentally. It’s not just that the topics are different – the emphasis and approach have also moved on.

The very first issue of Peak Performance (October 1990) carried an article on dehydration in runners, comparing the benefits of plain water with those of dilute glucose solutions, which are more isotonic and therefore absorbed more rapidly – all sound stuff, which has since been confirmed in a wide range of studies. Go into almost any supermarket today and you’ll find a large number of sports drinks aimed at maintaining hydration through isotonicity. The difference in 2004, however, is that by using soluble long-chain glucose polymers instead of simple glucose, it’s now possible to create an isotonic hydrating drink which also supplies significant amounts of carbohydrate to working muscles.

That same issue also included an article on free radical-induced muscle damage, presenting new evidence that the antioxidant vitamins A, C and E, supplemented in high doses, might be able to reduce it. In the intervening years, research in this area has mushroomed and antioxidant supplementation among athletes has become the norm rather than the exception. However, a decade-and-a-half down the line we’re also beginning to understand just how complex this area of nutrition really is, and to see that the reflex ’90s reaction of reaching for the supplement bottle is far too simplistic. Only last month, PP presented new research on antioxidants, which not only illustrated the difficulty of assessing free radical damage in athletes but also suggested that, far from protecting athletes and enhancing their performances, large doses of antioxidant nutrients may actually cause cellular damage and impair performance!

Another consistently topical subject over the last 14 years has been the relationship between carbohydrate intake and performance. The importance for athletes of maintaining muscle glycogen stores via a carbohydrate-rich diet and maximising them before long endurance events was already well documented – hence the widespread use of ‘carbohydrate-loading’ techniques. However, the second issue of PP (November 1990) presented an emerging consensus that the traumatic depletion phase of the classical carbohydrate-loading regime (where athletes deliberately deplete glycogen stores by exhaustive training and low carbohydrate diet) was no better in practice than simple tapering while consuming a high-carbohydrate diet for five days! Good advice, which has stood the test of time and further research.

Back in 1990, the prevailing view was that carbs were much of a muchness, whose job was simply to provide fuel for muscles. But during that decade it became clear that the ‘glycaemic index’ and release rate of different carbohydrates had important bearings on when they should best be consumed in relation to training. We also began to understand the intimate links between carbohydrate and protein metabolism and, particularly, that carbohydrate can exert a powerful protein-sparing effect in the body. And only recently new research reported in PP showed that consuming ample carbohydrate, both before and during prolonged bouts of strenuous exercise, can help protect the immune system. Bringing this collective wisdom together has enabled athletes to fuel themselves better, both through diet and specialist drinks, which has, in turn, enabled them to work harder, train longer and still recover more rapidly!

Possibly one of the most exciting developments in sports nutrition over this period has been the rise of creatine supplementation. When PP was first launched, creatine was pretty much unheard of as a routine sports supplement, but two years later came reports of beneficial effects experienced by some members of the British squad at the 1992 Barcelona Olympics. Over the next 10 years, a large amount of scientific research confirmed the benefits of creatine use, particularly for power, strength and sprint athletes. The use of creatine is now commonplace, with supplements widely available at a fraction of the original cost.

In the 14 years since PP was launched, there has been a growing tendency within the sports supplement industry to pick a random substrate from an extremely complex metabolic pathway and market it as the next performance-enhancing pill. But, unlike so many examples of this practice, creatine supplementation turned the world of sports nutrition on its head precisely because it was an extremely rare example of success in putting more of an energy-producing metabolic precursor in and getting more energy out as a result!

The flip side of progress It is hard to discuss progress in sports nutrition without mentioning the flip side. Over the last 14 years our understanding of the various biochemical pathways involved in the intricacies of metabolism has grown enormously – and so has the technology to synthesise metabolic intermediates and precursors involved in these pathways. Back in the ’80s, the nutritional supplements available to most athletes were pretty straightforward and familiar: vitamins, minerals, protein and carbohydrate powders etc. Yes, some athletes took drugs, but the boundaries between nutritional supplements and drugs were fairly clear. How different it is now!

The quest for that little something extra to lift performance has spawned a huge variety of ‘sports supplements’ which, although not drugs, are hardly naturally-occurring substances either. As a result, the distinction between a nutrient and a performance-enhancing substance has become increasingly blurred. The fact that many of these products are launched without adequate research to verify their efficacy, and are therefore a waste of an athlete’s time and money, is bad enough. Far worse, though, is the fact that a significant number of these supplements contain ingredients that can cause athletes to fall foul of the rules and regulations governing their sport. Even a bogstandard vitamin supplement could theoretically land an athlete in hot water because of inadvertent contamination by other, more ‘exotic’, substances present in the manufacturing environment.

So what developments can we expect in the next 14 years? While it’s not possible to predict the ‘next creatine’, there will almost certainly be trends, one of which will be an enhanced understanding of the complex interrelationships between different aspects of sports nutrition. Back in 1990, the prevailing view of sports nutrition was far more simplistic and compartmentalised. You want to slash your time for an event? Take supplement A. You want to build more strength? Take drink B. But there’s a growing realisation that this approach has limitations.

Tackling nutrition on a ‘day by day’ basis may not address longer-term issues, such as building optimum immunity or keeping injury and agerelated degeneration at bay, which are important for an athlete seeking to reach his or her full potential. Also, trying to boost one area of nutrition without considering its impact on other areas can invite problems. For example, taking iron supplements to boost iron status may impair the antioxidant defence systems, while relying too heavily on carbohydrate drinks during training may deprive the body of a large number of valuable nutrients and phytochemicals present in natural carbohydrates, which have been shown to exert a protective and immune-stimulating effect. As these subtleties and complexities become better understood, we will be able to make increasingly precise recommendations about the optimum nutritional practice for athletes from all disciplines.

Another area of development will almost certainly be ‘nutrigenomics’ – the interface between genetics and nutrition. Only this year, PP reported on new research showing that certain essential fatty acids can activate or deactivate the genes involved in fat metabolism and basal metabolic expenditure. As scientists become more skilled at unravelling the workings of our genes, it is increasingly likely that we’ll be able to match certain genotypes with optimum eating patterns and nutrient intakes. Rather than having to adopt a ‘one size fits all’ approach, athletes in 2018 may be routinely genetically tested in order to help them determine their precise individual requirements for optimum nutrition!

On the theme of testing, it is also likely that technology will enable faster, cheaper and more reliable testing of nutritional status. This will help eliminate much of the imprecision that currently exists when assessing athletes; not only will sports nutritionists and coaches be able to devise more tailored nutritional programmes for their athletes, but they will also be able to detect changes and warning signs (such as early signs of overtraining) more rapidly and reliably than at present.

Finally, the sports supplement and drinks industry will also continue to flourish, and with the use of increasingly sophisticated food technology (including GM), it is likely that we’ll see new and advanced products targeted at athletes. However, I also predict a growing realisation that whole, unprocessed natural foods are packed with thousands of naturally occurring health-promoting substances, which scientists haven’t even identified yet, let alone isolated and packaged into supplement form. This should mean that athletes will view these products for what they are – supplements to rather than substitutes for a fundamentally correct diet.

Whichever view you take, the next 14 years are likely to be every bit as exciting for sports nutrition as the last!

Andrew Hamilton