A balanced diet consisting of the following components will enhance sport performance.
Carbohydrates give energy
During times of high-intensity training, an athlete needs adequate energy intake to maintain body weight, minimise training effects and maintain good overall health. Low energy intakes can result in fatigue and a decreased performance level.
Carbohydrates are the main fuel source for athletes and are generally needed in larger amounts than applicable for the general population. However, factors such as total daily energy expenditure, type of sport, sex and age of the athlete, and environmental conditions need to be considered in estimating specific carbohydrate needs.
Good sources of carbohydrates are fruit (fresh and dried), fruit juice, bread, rice, pasta, couscous, potato, sweet potato, maize meal porridge, cereals, sport drinks and jelly sweets. Although vegetables are a source of carbohydrates, they contain very little and do not really contribute to the high carbohydrate needs of the athlete. It is important though not to exclude vegetables from the diet of the athlete.
Milk, flavoured milk and low-fat flavoured yoghurt are also a good source of carbohydrates and at the same time they contribute to the athlete’s protein needs.
Protein helps muscle recover
Protein requirements are slightly increased in highly active people and children. The requirement can generally be met through diet alone, without the use of protein supplements. Protein intake will help muscle to recover from damage incurred during training.
Some fat is beneficial
Fat is important in an athlete’s diet as it provides energy, fat-soluble vitamins and essential fatty acids. It should therefore constitute no less than 20 – 30% of an athlete’s total daily dietary intake. (For an athlete weighing 70 kg, this amounts to approximately 80 g of fat a day.)
Too much fatty or fried food on the day of a competition might lead to sluggishness. Fat decreases the transit time of food through the gut, which means that in the presence of a lot of fat, carbohydrates would not be readily available. Therefore, limit the use of fatty or fried foods on competition days.
Fluid helps the body stay cool
Dehydration decreases exercise performance. It is important for athletes to consume adequate fluid before, during and after exercise.
If you are an athlete or a gym fanatic, consider using dairy products like low-fat milk and low-fat yoghurt to improve your performance and ensure that your muscles recover after a strenuous workout. Athletes require additional protein after exercise to replace muscle protein that was broken down during exercise and to promote muscle repair and growth. Because dairy products are packed with high-quality protein, they are ideal for post-exercise muscle repair.
How much protein should you eat after exercise?
Most athletes know that they need to restore carbohydrates after exercise. However, research shows that if you add some protein (0.2 – 0.4 g/kg bodyweight) to your carbohydrates (0.8 – 1 g/kg bodyweight) immediately after exercise you will improve your body protein balance and boost glycogen storage. For example, a 70 kg athlete should have 14 – 28 g protein and 57 – 70 g carbohydrate after exercise. Practically, this equates to a meal of approximately 350 ml flavoured milk and two slices of bread with 30 g cheese.
Which protein foods can you eat after exercise?
Dairy is an excellent source of high-quality protein, which includes all the essential amino acids needed for muscle recovery. Low-fat dairy products like milk, flavoured milk, drinking yoghurt or cottage cheese are good choices and are often recommended as post-exercise snacks. Other sources of low-fat, high-quality protein are skimmed milk, whey or casein (ready prepared retail products on the market), skinless chicken (white meat), fish and egg white.
Muscle damage
So-called Exercise-Induced Muscle Damage (EIMD) can cause sore muscles and decrease muscle performance. By including protein in a post-exercise meal, you will provide your body with critical amino acids, which will improve muscle protein repair and muscle growth. This will not only help you build that "six-pack" but also speed up recovery and lower the risk of injury.
Supporting scientific evidence
Recent scientific research demonstrates the positive impact of dairy products on muscle recovery and muscle gain:
- Milk (low-fat) consumed 20 to 30 minutes after resistance exercise, which damages muscles, was found to reduce EIMD. In this study, the athletes improved their subsequent training performance and recovered faster.
- Yoghurt was found to decrease muscle damage and inflammation and increase antioxidant capacity after prolonged exercise.
- Chocolate milk was identified as an effective alternative to commercial sports drinks, because it helps to sustain performance in subsequent exercise sessions. The high carbohydrate, protein and mineral contents of chocolate milk are regarded as “critical recovery factors”.
- Eating a bowl of cereal with low-fat milk or drinking a flavoured milk drink is as good at helping muscles recover after exercise as commercially available sports drinks, but with the added benefit of providing protein.
Practical diet tips for athletes
Try the following to recover after exercise:
- Low-fat/fat-free milk
- Flavoured milk
- Drinking yoghurt
- Low-fat flavoured yoghurt
- Dairy fruit smoothie
- Cheese sandwich or a potato with cottage cheese
- Cereal with low-fat milk
Changes to body weight or composition should never compromise energy intake required to sustain performance. Severe energy restrictions or weight loss practices in which one or more food groups are eliminated may put an athlete at risk for micronutrient (vitamins and minerals) deficiencies. Athletes should strive to consume foods from all the food groups to provide at least the recommended daily allowances for all micronutrients from food.
Athletes who need to lose weight to improve their performance should consult a dietitian for advice.
The intake of sports drinks – whether homemade or commercial – should be limited to during activity as they are specifically formulated to supply the fluid, carbohydrates and electrolytes that the active body needs.
Fluid intake during exercise is important to prevent dehydration and help keep the body cool. Flavourants encourage regular drinking. Diluted fruit juice (two cups of water for every cup of juice) can be used for fluid replacement, although it may not eliminate thirst to the same extent as a sports drink.
A 6% carbohydrate solution (6 g carbohydrate per 100 ml drink) strikes the optimal balance in taste, rapid fluid absorption and energy supply to fuel working muscles. Undiluted juice or carbonated 
soda should be avoided because they typically contain too much carbohydrate (10– 12%) and may cause gastric discomfort and delay gastric emptying. Multiple carbohydrate sources are preferred because this helps stimulate fluid absorption.
The electrolyte content of a sports drink should attempt to replace both the potassium (30 mg/250 ml) and sodium lost through sweat. A potassium concentration of 30 mg/250 ml should be adequate. Sodium intake of approximately 100 mg/250 ml enhances the taste of a sports drink, facilitates the absorption of fluid and helps to maintain body fluids. Sodium may also stimulate voluntary drinking.
Ingredients other than fluid, carbohydrates and electrolytes are unnecessary in sports drinks because the body cannot use them during exercise.
- Caffeine (found in beverages such as iced tea and certain soft drinks) should be avoided because it promotes fluid loss (diuresis) and can have side-effects that can influence performance negatively.
- Herbs, e.g. guarana, gingko biloba, ephedra and ginseng, are often added to sports drinks, but research show no conclusive performance benefits of these substances. Experts question the safety and benefits of these herbal ingredients.
"Changes to body weight or composition should never compromise energy intake required to sustain performance."
What practical advice can athletes follow to ensure optimal benefit from sports drinks?
- Choose a sports drink with a 6% carbohydrate solution.
- Avoid unnecessary substances, e.g. herbs, vitamins, minerals and caffeine in sports drinks.
- Drink small amounts regularly during training (according to schedule or in all drink breaks provided).
- Avoid the intake of sports drinks outside activity periods.
- Monitor drinking hygiene. Athletes should each use their own water bottles and wash and rinse them thoroughly after use.
- Pack a favourite sports drink for training sessions and competitions.
Drink flavoured fluids through a straw to limit the amount of contact between the sports drink and teeth. This can reduce the risk of dental decay.
How should an athlete start a competition day?
If you have to travel long distances or need to make an early start before a game, pack an on-the-run breakfast.
In situations where nervousness or excitement decreases appetite, use meal replacements or flavoured milk as a liquid meal.
Is the food supplied at sports events recommended for athletes?
Food available from vendors at sports events (e.g. boerewors rolls, potato chips, chip sticks, meat pies, etc.) is not ideal for athletes on competition days, as they are often high in fat and protein. Such foods take longer to digest than carbohydrates and therefore can cause indigestion and nausea.
If food has to be bought at the event, choose healthy options:
Plan and pack your own food!
Why do athletes take supplements?
As training programmes become more demanding, the role of nutrition becomes ever more important to sustain good performance. A varied diet that meets the energy needs of a training athlete should provide all the essential nutrients in adequate amounts to ensure optimal adaptation to training and performance.
However, over the years a culture has developed that supplements can in some way compensate for poor food choices and the increased stresses of modern life. Supplements are often used:
- to compensate for an inadequate diet
- to meet abnormal demands of hard training or frequent competition
- to benefit performance
- to keep up with team mates or opponents
- on recommendation of a coach, parent or other influential individuals.
Although some sports supplements can contribute to an athlete’s performance, they cannot replace the value of good nutrition and a balanced training programme. Many athletes put so much effort into finding a supplement to enhance their performance that they forget about the role of training, skills, equipment, adequate rest, good nutrition, and a positive mental attitude – which all have a much larger impact on improving sports performance.
Are supplements regulated in South Africa?
There is no governing body to control or regulate the production, distribution or marketing of sports supplements in South Africa. Therefore there is no way to ensure their safety or efficacy and products can be marketed with very little control over the claims and messages they provide – a situation of which many companies take full advantage.
According to the World Anti-Doping Agency (WADA) “most supplement manufacturers make claims about their products that are not backed by valid scientific research, and they rarely advise the consumer about potential adverse effects. The supplement industry is a money-making venture and athletes should get proper help to distinguish marketing strategies from reality.”
Supplements are big business. Athletes are often drawn by the images of picture-perfect bodies and the promise of enhanced performance or recovery by a certain product. Yet, there are many potential risks and little to no benefits.
What are the risks of using sports supplements?
Contaminants, particularly anabolic steroids and other prohibited stimulants, have been found in various supplements. This means that an athlete’s use of a sports supplement may lead to a positive doping test.
How should a supplement be chosen?
Supplements can be divided into Weight gain or muscle build supplements, Weight loss supplements and Performance enhancer supplements. To compare the effect of the different supplements, see te table below:
What should athletes know about all the different ingredients in sports supplements?
Whey protein is found in milk and has been promoted as easily digested and absorbed. Manufacturers claim it stimulates muscle growth better than other protein sources. However, studies do not confirm this in athletes and it is one of the most expensive supplements on the market. Although it contains useful essential amino acids, food is a better protein source.
Vitamins and minerals are essential for good health. Athletes may well require more vitamins and minerals than sedentary people, but it is important to optimise food intake first before turning to supplements.
A standard dose tablet is unlikely to cause any harm and can help remedy any possible deficiencies in the diet. But there is no justification for taking lots of extra vitamin supplements: very little evidence exists for the benefit to athletes, except in the case of documented deficiencies, which are rare.
It is possible to ingest toxic levels of some vitamins and minerals over time. Therefore, high-potency and megadose brands should be avoided.
Also known as “andro”, it is a precursor to the natural hormones testosterone and oestrogen, both of which are important for growth and repair. However, studies fail to show any benefit from taking this supplement. Bottom line: don’t buy it!
Chromium picolinate is advertised to decrease body fat, increase muscle mass and energy. Chromium occurs naturally in our food supply and works on carbohydrate metabolism. Studies fail to show any benefit of supplementation to athletes.
Caffeine is a legal and known stimulant. Athletes have used caffeine to enhance performance for decades. Known side-effects include irritability, nervousness, increased heart rate, headaches and loss of sleep. If you are not a regular caffeine user it would be wise not to start, as it can be very addictive.
These supplements are very popular and expensive. However, they are often loaded with extra ingredients and impurities. Supplementation is unnecessary given the already high-protein diets consumed nationwide. Strict vegetarians and endurance athletes may benefit from these owing to their lower-protein diets and an increased need for total body protein. But massive doses of protein will not turn into extra muscle.
These individual components of protein molecules are sold as additives, commonly labelled as branched-chain amino acids. They are available as tablets, powder or in liquid form. Supplementation is unnecessary since amino acids are found abundantly in the existing diet.
These products are a compact way of ingesting a variety of nutrients and can be very useful to busy athletes. Solid bars are better as they provide more actual nutrients than energy drinks. Regular sports drinks are most useful during and after competition to replace fluids; yet, for short duration activities water alone is more than adequate to replace lost fluid.
"Vitamins and minerals are essential for good health. Athletes may well require more vitamins and minerals than sedentary people, but it is important to optimise food intake first before turning to supplements."
Why are creatine supplements so popular?
Creatine is found naturally in skeletal muscle tissue and liberates energy (adenosine triphosphate) ATP for brief high-intensity exercise. The human body can make creatine from amino acids that come available after the digestion of protein. Creatine is also found in food sources with meat and fish being the richest natural sources of creatine. As a supplement, creatine is available in powder, liquid and capsule form.
Creatine supplements have become popular amongst competitive athletes in an attempt to enhance energy production, increase the body’s ability to maintain force and delay fatigue. However, products containing creatine do not work by themselves; instead, they help athletes maximise their training or performance only because of the improvement in recovery time. Strength and muscle mass changes associated with creatine use therefore occur because athletes are able to do more work but with less fatigue in a specific period in time.
Creatine supplementation has been shown to be most beneficial in exercise involving repeated sprints or bouts of high-intensity exercise, separated by short recovery intervals. However, not all human studies have shown that creatine improves athletic performance nor that everyone responds the same way to creatine supplements. People who tend to have naturally high stores of creatine in their muscles don’t get an energy-boosting effect from extra creatine.
At present creatine seems relatively safe for use with minimal to no side-effects if taken as directed. Failure to do so may negate its proposed benefit or even lead to decreased performance because of intestinal distress.
Why is the use of creatine supplements controversial then?
Creatine as a supplement has been studied for shortterm use only. Although creatine is not banned by the International Olimpic Committee (IOC), using it for athletic performance is controversial, because:
- the long-term consequences of creatine use or the effect of overdosing is unknown
- there have been anecdotal reports of an increased risk of muscle cramps, strains and tears
- there is concern over kidney complications
- there are no data on the effects of creatine supplementation on other organs that store creatine (i.e. heart, liver, brain).
- supplements have a high risk of being mislabelled or contaminated with banned substances. Are creatine supplements safe for young athletes?
There is concern over the marketing of creatine-containing supplements to teens seeing that neither safety nor effectiveness in persons younger than 18 has yet been tested.
The efficacy of creatine supplementation in children and adolescents are questioned for the following reasons:
- Children and adolescents rely more on aerobic than anaerobic metabolism. The goal of creatine supplementation is to enhance anaerobic metabolism. Supplementation in children and adolescents would therefore have a limited effect.
- Adolescents appear to be able to regenerate highenergy phosphate during high-intensity exercise and improve performance in short-term, highintensity exercise through training. The need for supplementation is therefore reduced. Performance during growth tends to be limited by mechanical factors rather than by the relative contribution of the aerobic and anaerobic energy systems.
Creatine supplements are therefore not recommended for children or teens. Factors such as optimal training, sufficient rest and sleep, good nutrition, the right equipment, and the correct mental attitude will produce much larger performance gains than any supplement. Any athlete will improve their performance by focussing on these basics, rather than relying on a ‘quick fix’ that most probably doesn’t work or has potential adverse effects.
Can sport supplements benefit young athletes?
Providing children with supplements creates a false sense of security and may encourage faulty eating habits.
Another disadvantage of supplement use is that young athletes may erroneously associate improvements in performance with whatever supplements they may be taking. They may be less likely to attribute progress to training, hard work and a balanced diet. This type of false reinforcement may also encourage children to try other types of supplements and substances and lead to a snowball effect with undesired consequences.
For the young athlete, the key to health and performance cannot be found in any one food or supplement, but in a proper combination of foods that provide many different nutrients that the body requires. Variety and moderation is the best strategy to achieve balance.
References
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