Supplements For Performance
The following is a precis of the presentation given on 3rd February 2011 at Lilleshall National Sports Centre in conjunction with Lilleshall Sports Injury Rehab Ltd.
For more information on supplements, click here to visit our Supplements Research and Information pages.
Introduction
A healthy, balanced diet is as relevant for athletes as it is for the general population, Even for athletes, there is no need for an excessive intake of any nutrients. The key difference will be the AMOUNT of energy required. Everyone, regardless of their status, should aim to eat a balanced diet as shown in the Eatwell plate from the Food Standards Agency.
A Bit About Supplements
Nutritional supplements are known as 'ergogenic aids' meaning that they are designed to increase the body's ability to perform work.
Before taking supplements, it is advised to:
- Do your research and check with a professional body if you are unsure about anything
- Set your budget
- Chose your brand carefully
- Always stick to the manufacturer's dosage guidelines
Whilst taking supplements, it is advised that you:
- Watch out for side-effects
- Monitor your performance for improvement or decline
- Re-assess your supplementation protocol after a set period of time
Supplements For Endurance Performance
Carbohydrate
Carbohydrate is probably the most commonly used 'endurance' supplement and carbohydrate supplementation is one of the most well-researched areas of sports nutrition. Carbohydrate supplements contain glucose, glucose polymers and/or maltodextrin and the aim of these products is to provide the body with extra fuel during endurance exercise. By supplying more carbohydrate, which is the body's preferred fuel, endurance is likely to be improved. If carbohydrate is going to be used to improve performance, the athlete should 'start early' and aim for 100-150ml every ten minutes or 500ml/hour.
There are different types of carbohydrate drinks which are categorised according to their carbohydrate concentration.
-
Isotonic drinks have the same carbohydrate concentration as blood meaning that they are rapidly absorbed by the body and provide fuel very quickly after consumption. These drinks account for the body's fluid and fuel needs simultaneously.
-
Hypotonic drinks contain carbohydrate at a lower concentration as compared to blood and are best used as rehydration drinks - they provide minimal amounts of fuel. These drinks are of limited use in sport but are now being marketed towards the fitness market as they are low in calories.
-
Hypertonic drinks are highly concentrated and are often used to top up muscle glycogen stores. These are not effective at rehydrating and may actually dehydrate a person further as they will draw water out of the blood stream.
Sodium is often added to sports drinks to as it:
-
increases the drive for thirst and encourages fluid uptake
-
increases the absorption of fluid and carbohydrates
-
increases fluid retention by the body
-
decreases uring production
Caffeine
Caffeine is a naturally occurring, legal and socially acceptable stimulant which acts on the Central Nervous System. This has been used as a nutritional supplement as it increases fat oxidation during aerobic metabolism and therefore it has been theorised to improve endurance performance.
The research behind caffeine intake has shown that it is effective at improving mental and physical performance in endurance and cognitive tasks but it is less effective in those who use it frequently. What's more, it can cause the jitters and it stimulates smooth muscle contraction in the bladder and bowel.
Glutamine and Branched Chain Amino Acids (BCAAs)
Glutamine is an amino acid (AA) and it is purported to aid recovery from strenuous exercise & prevent muscle catabolism. BCAAs can be used as a fuel during ultra-endurance exercise. There is some evidence to suggest that these products are capable of improving performance but it is limited. No sound research has shown a direct improvement in performance and supplementation with these products seems to only be relevance for those people training and competing regularly in events that last more than 3 hours.
Antioxidants
Certain vitamins (A,C & E), minerals (selenium) and plant compound (lycopenes) are known as antioxidants. Antioxidants can 'mop-up' the free radicals produced during exercise and this prevents cell damage. Although there is evidence to show that exercise increases free radical production and cell damage and that antioxidants prevent free radical damage, there is no evidence to show that antioxidants improve performance. Antioxidants are natural substances, therefore they are safe to take as long as the recommended doses are not exceeded.
Supplements For Strength & Power Performance
Whey Protein Isolate
This protein is produced from the whey component of milk and has a high biological value (HBV). A HBV means that the protein can be readily and rapidly absorbed by the body. Many studies have demonstrated the value of protein supplements as they stimulate muscle synthesis (growth) immediately before, during or after exercise. However, supplementation with protein outside of exercise will not result in muscle growth.
Protein supplements can be expensive but they do offer a convenient, low-fat way for athletes to meet their increased protein requirements. Carbohydrate is often added to protein supplements to enhance their effectiveness.
Creatine
Creatine is a naturally occurring substance that is the body's 'immediate' energy source. The theory behind creatine supplementation is that it will increase the levels of 'free creatine' and 'creatine phosphate' in the muscles. The result of this will be that there is more creatine available to fuel high-intensity activity and that replenishment of the creatine stores following these activities will be quicker.
Creatine supplementation is very well-researched and it is most effective for improving performance in activities involving repeated high-intensity bursts. However, it is estimated that around one third of the population will be 'non-responders' to creatine supplementation. What's more side-effects have been reported so it is important to stick to the recommended dosage.
HMB
B-Hydroxy-B-Methylbutyrate or HMB is a naturally occurring substance found in catfish and grapefruit. It is used as a supplement as it is an anti-catabolic agent during periods of high-intensity activity. There are no known side effects or health implications but it is important to stick to the manufacturer's recommendations when using it. HMB needs to be taken in divided doses in order to gain the maximal effects from the supplement.
Summary
A healthy, balanced diet is essential prior to any supplementation regime.
Supplementation with proven, safe products may enhance performance for some athletes.
It is important to stick to the manufacturer's recommendations when using supplements.
For information on restricted products and methods, visit www.wada-ama.org