Late in 2003 the IOC brought together a group of sports nutrition experts and researchers from around the world to discuss and revise its consensus statement on sports nutrition. Part of this consensus statement says:
"A varied diet that meets energy needs will generally provide protein in excess of requirements. Muscle mass is maintained or increased at these protein intakes, and the timing of eating carbohydrate and protein may affect the training adaptation." - IOC consensus statement on sports nutrition 2003, Journal of Sports Science, 2004: 22.
What is Protein?
Protein is part of our diet and is the “group” term for the delivery of a range of amino acids. Our diet provides us with 28 amino acids, of which 8 are essential as they cannot be manufactured within our bodies. These amino acids are ingested as whole protein and are then broken down to their individual components and either used or are stored and an amino acid depot ready for our bodies to make new proteins (for example, muscle, hair, nails, skin, enzymes, hormones, antibodies, etc).
Different protein foods contain different amino acids, and in varying quantities – so it is important to consume a range of protein-containing foods. The main use of protein is in growth and repair, although it is also a source of fuel to our body, especially if carbohydrate stores (glycogen) are low.
Foods rich in protein include meat products (including poultry, fish and seafood), eggs, dairy products, legumes, nuts and seeds, and tofu. Breads and cereals, rice and pasta also contribute useful amounts of protein to our diets.
Do Athletes need more Protein?
It is well recognised that athletes require more protein than sedentary people. What is interesting is that protein requirements of both strength and endurance athletes are very similar – around 1.2-1.7g/kg body mass (compared to 0.8g/kg body mass for sedentary people). Strength athletes require more protein for maintenance and growth of muscles, whereas endurance athletes require more protein to repair tissue damage (such as blood cells, etc) and also as a source of fuel. The good news is that most athletes achieve this higher protein need quite naturally, simply by the fact that our traditional diets aren’t low in protein, and because athletes tend to have higher energy intakes. This level of protein intake does not constitute a HIGH PROTEIN DIET, however.
Is whey the best type of Protein?
In the past, egg protein was considered the most complete, and many “protein” supplements were based on either egg or skim milk protein (which is a combination of whey and casein proteins). More recently, the supplement industry has pushed isolated whey protein as the optimal source for athletes – unfortunately with very little scientific backing. What we understand now is that different proteins are absorbed at different rates (much like the glycaemic index for carbohydrates) and have different functions. Whey protein is absorbed rapidly from the gut, and elevates blood amino acids levels but only for a relatively brief period of time. Whey protein may also boost immune function. Casein, on the other hand, is absorbed more slowly but maintains an elevation in blood amino acid levels for a longer period of time than whey. Casein also has an anti-catabolic action, which means it reduces muscle protein breakdown, which whey protein doesn’t do. Soy protein is also promoted heavily in some sports, and has an advantage of containing some antioxidants. The bottom line is that it’s probably best to include a variety of protein types in our diet, particularly after exercise, and that timing is more important than type, or probably even the amount.
Is it better to take Amino Acids, rather than Protein?
Amino acids have also been made popular by some supplements companies, which is partly because many of the studies on protein metabolism use amino acid concentrates. However, the reason scientists use amino acids is because they can more easily quantify exactly how much amino acids they are providing to subjects and they can label and trace their movement in and out of muscles, not because they are a better source. It is important to remember that we receive more than just amino acids from food – most protein sources are also excellent sources of other important nutrients for athletes, such as iron, zinc, and calcium. Also, excessive amounts of one single amino acid can disrupt overall protein balance since all of our body proteins require different proportions of the various amino acids. Remember that 5g of amino acids (as capsules) is effectively 5g protein, which you can achieve much more cheaply by eating an egg!
Some amino acids have been studied to learn more about their specific functions in sport. For example, branched-chain amino acids are a group of 3 amino acids which have been researched in the area of “central” fatigue (i.e. the brain and nervous system) in prolonged endurance exercise. Although taking BCAA’s can delay this fatigue, consuming carbohydrate works equally well, if not better. Another example is glutamine and immune function. Researchers found that glutamine levels fall at the same time as some immune parameters during prolonged exercise. Whilst supplementing athletes with glutamine stops the fall in blood levels, it does not alter immune function.
Is timing important?
We all know that taking in carbohydrate soon after exercise promotes greater glycogen replenishment in the muscle. Recent protein studies have shown a similar effect with protein. If you don’t eat after resistance training, you will actually create a breakdown of muscle. If you eat protein, the muscle will actually start to take up protein, rather than break it down. Even more interesting are a couple of studies which have looked at the effect of eating protein PRIOR to resistance training – and the effect on protein uptake after training seems to be even better than just eating protein after the session. So, timing is very important. The optimal amount of protein after exercise is around 10-15g.
What about other nutrients?
Studies have shown that consuming either protein OR carbohydrate after resistance exercise will reduce muscle breakdown and promote muscle generation. More importantly, the outcomes from a number of studies show that combining the two has an even greater effect - ie carbohydrate AND protein work together produces a more positive protein uptake by muscle. There is even some evidence to suggest that the protein also supports greater carbohydrate uptake when there has been some muscle damage.
Don't I need more Protein if I’m trying to bulk up?
While resistance training does increase protein requirements, as indicated above this is no greater than that needed for any other type of training. The key ingredients to bulking up include the right training program (and a willingness to train hard!), and a high energy intake. Many athletes struggle to achieve the energy needs for gaining muscle mass, especially if they have a busy schedule of training, work / study and home commitments. Get yourself organised to eat regularly throughout the day (5-6 meals / snacks at least), make use of your fluids by drinking milk, juice, cordial and sports drinks, and eat more energy dense snacks such as dried fruit and nuts and cereal bars.
Won't eating more Protein help me lose body fat?
To lose body fat, you need to eat a little less energy than you burn. High protein weight loss diets can work in the short term for non-exercising people because they reduce total energy intake. Protein tends to satisfy your appetite the best, and if you take out carbohydrate, then you remove out a lot of food sources.
Whilst a non-exercising person might get away with dropping out carbs and increasing protein, someone who’s training hard won’t. Dropping carbs will result in increased fatigue, an inability to train effectively, and may reduce your immune function, making you more prone to getting sick. If you eat a high protein diet AND maintain your carbohydrate intake as well, then you may very well gain body fat!
What happens if I eat too much Protein?
There is no strong evidence that a high protein intake is dangerous to our health nor results in body fat gain, although we do know that high protein intakes can reduce calcium uptake into bones. More importantly for athletes, eating too much protein leaves little room for achieving carbohydrate needs – which is most likely to compromise training. Also, high protein diets are generally more expensive.
- Protein is important, but you don’t need to eat massive amounts. Make sure you base each meal and snack on carbohydrate but with a source of protein included, and don’t forget the importance of a balanced diet as well.
- Eat soon after training, using a combination of both protein and carbohydrate (see enews 12: recovery). Note: although most of the protein research has been with resistance training, there is no reason to believe the same effects would not be seen after a moderate-high intensity paddling session, or a prolonged endurance session.
- Go for real food wherever possible, but supplements such as protein plus can be useful if you’re short of time or don’t feel like eating.
- For weights sessions, have a protein-based snack within 30-60 mins prior to the training session as well as afterwards.
Good examples of Protein and Carbohydrate snacks for recovery include
Cereal with low fat milk
Fruit with yoghurt
Sandwiches or rolls with lean meat / chicken / low fat cheese / tuna fillings
Dried fruit and nuts mixtures
Eggs or baked beans on toast
English muffins with peanut butter
Low fat milkshake / smoothee / flavoured milk / protein plus/ sustagen
Jelly and custard
In my experience, most athletes don’t use supplements very much, however in the lead up to Beijing now is a good time to remind you of some of the potential issues you COULD face.
What is a Supplement?
The definition of a Supplement can be a little grey, which is where much of the confusion can lie. In most instances, it can be defined as something which provides a nutrient, or range of nutrients, in larger amounts than those found commonly in food. However, it also can include powders and capsules which are promoted in addition to, or in replacement of, food. Supplements don’t necessarily have to be promoted specifically to athletes in order to be a problem.
Why is there a problem?
Between 2000-2002, the IOC had an accredited laboratory test 634 sports supplements products from 13 different countries. Of these supplements, 15% tested positive to steroids and prohormones which were on the banned substance list of the WADA code. These substances were not declared on the label of the supplement, and if consumed would have resulted in a positive doping test. Furthermore, 15% also didn’t contain the “active ingredient” which was MEANT to be in there (in other words, if it was a Ginseng supplement there were no traces of Ginseng found in the product).
If you thought that this would have made manufacturers reassess their quality control procedures and reduce the risk of cross contamination, think again! Just this year a laboratory in the UK tested a range of over-the-counter supplements purchased in the USA. These included products promoted for weight loss, muscle gain, hormone regulators, testosterone boosters, protein supplements, post-workout recovery and energy drinks. Of the 54 products analysed, 25% tested positive for a banned substance which was NOT stated on the label. These banned substances included nandrolone, DHEA, androstenedione, androstenediol and ephedrine (amongst others). The most predominant products to test positive were testosterone boosters (67% tested positive) and weight loss supplements (29% tested positive).
The same laboratory who undertook these tests also systematically tests products for banned supplements for companies in the UK, Europe and the USA who are wanting to sponsor athletes and provide evidence that their products are safe. It has been reported that of these tests, 2.8% of products have tested positive, and they have also found that even the capsules in which some products are packed have tested positive for banned substances.
Why is this? Some of it is due to inadvertent cross-contamination by using large scale packing equipment to pack a range of products. Unlike the pharmaceutical industry, where all equipment has to be thoroughly cleaned between batches and raw ingredients held securely, the quality control procedures in the supplements industry are not strictly regulated. Therefore, if a batch of product y is packed immediately after product x, which happened to contain a banned substance, there is a risk that there are some remnants of product x still around in the packing equipment which will be mingled with product y. It only takes a minute amount of nandrolone (2.5-5 micrograms) to test positive. There are also potential issues with the storage of the raw ingredients in the same large area. Then, some of it is due to deliberate inclusion of a banned substance in a product without declaring it. In some instances, the source of the raw ingredients is also of concern.
So, what can I do to check?
That’s the tricky thing. Since the majority of these contaminants aren’t listed on the label, there is no way of checking whether it’s likely to be a problem. You can have a product tested by a laboratory, but that still provides no guarantee for EVERY batch of the product. Calling your National Anti-Doping Organisation (NADO) is unlikely to resolve this question either as, if they test, they are unable to test every batch of every supplement available in your country, let alone throughout the world. So, generally it is recommended that you avoid taking supplements. Alternatively, ask the manufacturer for a written guarantee that the product you’re taking doesn’t contain any banned substances, and make sure you write down EVERYTHING you’re taking if you’re asked to undergo a drug test.
Regardless, if you test positive for a banned substance, no matter how inadvertent it may be, YOU are responsible for this and it will still be considered a positive test.
Don’t be fooled either by products which claim their ingredients are “pharmaceutical grade”. This may very well be the case, however they are not packed in a pharmaceutical plant and are therefore still open to the same risks as any other ingredient. Similarly, while there maybe be organisations in some countries which control the safety of ingredients brought into their country and approve supplements for sale, the internet provides a multitude of options which these organisations cannot control. For example, in Australia you cannot legally purchase DHEA whereas in the USA it’s available even in supermarkets, with no control over purchase.
Are there any exceptions?
Generally, products manufactured within the food industry or within the pharmaceutical industry are generally safer as the standards within these industries are tighter. Hence, multivitamins or individual vitamins / minerals from a pharmaceutical company tend to be safe, as are sports drinks and some liquid meal supplements (e.g. Ensure, Sustagen).
- Think very carefully about the need for a supplement BEFORE taking any.
- Find out exactly what the supplement is meant to do and who manufactures it.
- Ask the manufacturer for a written declaration that the product contains ONLY what is stated on the label and check carefully where they source their ingredients and how / where the product is packed.
- Try and get what you are needing from food.