Top-Rated Free Essay
Preview

A Critical Review of Contemporary and Popular Reports Within the ‘Lay’ Literature on the Use of Nutritional Supplements for Performance Benefits.

Powerful Essays
1909 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
A Critical Review of Contemporary and Popular Reports Within the ‘Lay’ Literature on the Use of Nutritional Supplements for Performance Benefits.
A critical review of contemporary and popular reports within the ‘lay’ literature on the use of nutritional supplements for performance benefits.

There is an endless list of ergogenic aids that claim to enhance sports performance that are religiously supplemented by amateur and professional athletes. Almost half of the general population have reported taking at least one form of dietary supplement, and the vast majority, if not all professional athletes use legal supplements, with a certain few resulting to using illegal methods to improve their performance (Ahrendt, 2001). Currently, the Australian Institute of Sport (AIS) provides a program list of supplements classified into four groups according to their effectiveness, safety and legal status as reviewed in scientific studies. (AIS, 2011). The supplements in; Group A are supported for use in specific situations in sport; Group B are considered for provision to AIS athletes only under a research protocol; Group C show little proof of beneficial effects and the supplements in Group D should not be used by AIS athletes. Creatine has been reported as the top-selling nutritional supplement in the world, mainly due to it being, affordable, relatively free from side-effects and because it works.
Creatine is made up of three amino acids; glycine, arginine, and methionine. The liver naturally produces about 1 gram (g) of creatine per day; the rest is mainly found in foods such as meat and fish. An average diet will also ingest about 1g of creatine per day. Creatine as a supplement can be taken in the form of a tablet or as a powder to be mixed with water. It is generally claimed (Smith, 2011) that supplementing creatine has several benefits for hard training athletes as when creatine is taken, it bonds with phosphate molecules to form creatine phosphate (CP). The phosphate molecules in creatine phosphate are then able bond with adenosine diphosphate (ADP) to form adenosine tri-phosphate (ATP), the energy currency of the cell, used in all cellular functions and muscular contraction. Therefore, it is believed that supplementing creatine will cause an increase in the body's ATP production leading to performance improvements and decreased fatigue in intense, short duration exercise such as weightlifting and sprinting (McArdle et al, 2007).
Additionally creatine is thought to benefit athletes as it improves hydration of muscle cells. (Mens Health, 2011). Creatine draws fluid from outside the muscle cell into the cell membrane. Due to the increase in water retention of the muscle cell, other ions such as nitrogen are drawn into the muscle cell leading to an increase in muscle protein synthesis allowing athletes to recover from exercise faster and increase muscle growth (Mens Health, 2011). Creatine supplementation is recommended to be specifically beneficial to athletes participating in high intensity exercise that require short, sharp bursts of energy. (McArdle et al, 2007). There is a considerable body of research studies that supports the efficacy of creatine in increasing body mass and performance in high intensity, short duration exercise. A study by Kraemer et al (1997) was undertaken to investigate the effect of creatine supplementation on muscular performance during high-intensity resistance exercise. The researchers compared the effect of 25g/day creatine supplementation for a week against that of a placebo on 10 repetition maximum bench press and squat in 14 active men. They found that there was no improvement in the placebo group, but those men supplementing creatine had significant improvements in both their maximum bench press and squat. Additionally, the participants who were supplementing creatine showed a body mass increase of upto 3kg. A similar study by Tarnopolshy and MacLennon (2000) also found that active men and women who supplemented creatine also showed an improvement in an anaerobic cycle test, 1RM leg extension and grip strength. The participants took a loading dose of 5g creatine, 4 times a day for 4 days, and followed this with a maintenance dose of 5g a day for 3 days. Dawson et al (1995) had found in a previous study that creatine supplementation can enhance both single and repeated short sprint performance when compared with a placebo group. Despite being arguably the most researched supplement, researchers have not agreed consistently on the exact dose to supplement. Most studies suggest that there should be a loading phase where typically no more than 300mg per kg of body mass should be consumed for 4-5 days, after this a maintenance phase of 30mg/kg body mass is required for the remainder of the course, most likely to be 2-3 weeks (Bird, 2003). Bird advised to not supplement creatine for longer than a month at a time as it can affect renal function, although there are very few studies that investigate the long-term effects of supplementing creatine and of these, there is no evidence to suggest short or long-term side effects of creatine supplementation. Carnitine is another very popular ergogenic aid; it was in the top 3 of reported dietary supplements taken by athletes at the 2000 Olympic games in Sydney. (Mens Health, 2011). Despite this, it is found in group B of the AIS supplements list.
Carnitine is a short chain of coboxylic acid that contains nitrogen, it is vital for normal metabolism as it is required for the transport of fatty acids from the cytosol into the mitochondria during the breakfown of lipids for the generation of metabolic energy.
A typical diet will contain 20-200mg of carnitine per day, this accounts for around 75% that is used by the body. The other 25% is synthesized in the liver and kidneys from the amino acids methionine and lysine. Similarly to creatine, the largest dietary sources of carnitine are meat, poultry, fish and dairy products meaning that vegetarians may only ingest as little as 2mg per day. It is claimed that supplementing carnitine will encourage faster post-exercise recovery from muscle fatigue and faster skeletal muscle tissue repair. (Holland and Barrett, 2011).
Carnitine is also believed to lead to an increase in endurance capacity. (Greig et al, 1987) suggest that carnitine will boost energy by stimulating the bodies burning of triglycerides as fuel, sparing the supply of glycogen stored in the liver for heavier exertion. Therefore, during exercise the body will burn fat at 75-80% of maximum exertion, thus less glycogen from carbohydrates is burned. Rebouche and Paulson (1986) claim that by carnitine supplements allow the body to access an otherwise unavailable energy source. The marketing of carnitine targets endurance athletes by stating that “metabolic stimulators” in carnitine enhance fat burning and spare glycogen. Because of this there is an appeal to body builders as an aid to reducing body fat. Studies have shown contrasting results as to whether the supplementation of carnitine can increase fat oxidation in sub-maximal exercise. Vukovic et al (1994) conducted a study analysing the effect supplementing carnitine of muscle carnitine and glycogen content during exercise in participants with purposely raised levels of triglycerides. Participants were asked to supplement 6g/day of carnitine for 7 or 14 days and compared with a placebo group. They all consumed 90g of fat 3 hours before cycling for 60 minutes at 70% of their VO2 max. Muscle biopsies were taken at 30 minute intervals and a blood sample was taken every 15 minutes. The study found that increased carnitine intake does not affect the amount of carnitine stored in muscle cells. They also found that increased levels of carnitine do not increase the rate of fat oxidation. The researchers went on to add their opinion that there is adequate muscle carnitine within the mitochondria to support lipid oxidation.
A meta-analysis by Brass (2000) also concluded that supplementation of carnitine does not increase muscle carnitine content, adding that the literature available of experimental clinical studies assessing the effect of carnitine on exercise metabolism or performance in healthy humans does not draw definitive conclusions. He further disregarded using carnitine as a supplement by suggesting that it also does not improve maximal oxygen uptake or metabolic status during exercise. However, there are some research studies that contrast this. Kraemer et al (2001) examine the influence of carnitine supplementation on muscle tissue disruption after high-intensity, high repetition exercise. They found that against a placebo, a daily carnitine supplement was effective in decreasing lower body muscle recovery time.
Although carnitine is one of the most widely used nutritional supplements, there is little conclusive proof that it is significantly effect on increasing performance and decreasing recovery time that the ‘lay’ literature suggests. In conclusion, using supplements as a professional athlete is essential because every possible extra benefit that they can attain should be utilised. Although many supplements claim to do a lot more than they actually do, there is evidence to suggest that even this placebo can give and extra benefit in the mind of an athlete.

Ahrendt DM. (2001). Ergogenic aids: counselling the athlete. American Family Physician. 63(5): 913-922.

Australian Institute of Sport. (2011). AIS Supplement Group Classification System. Available: http://www.ausport.gov.au/ais/nutrition/supplements/classification_test. Last accessed 4th January 2012.

Bird SP. (2003). Creatine supplementation and exercise performance: A brief review. Journal of Sports Science and Medicine. 2: 123-132.

Brass EP. (2000) Supplemental carnitine and exercise. American Journal of Clinical Nutrition. 72(2): 6185-6232.

Creatine Information Centre. (2011). How much and when should I take creatine?. Available: http://www.creatinemonohydrate.net/creatine_doses.html. Last accessed 5th January 2012.

Dawson B, Cutler M, Moody A, Lawrence S, Goodman C & Randall N. (1995). Effects of oral creatine loading on single and repeated maximal short sprints. Australian Journal of Science and Medicine in Sport. 27(3): 56-61.

Greig C, Finch KM, Jones DA, Cooper M, Sargeant AJ & Forte CA. (1987) The effect of oral supplementation with L-carnitine on maximum and sub-maximum exercise capacity. European Journal of Applied Physiology. 56: 457–460.

Holland and Barrett. (2011). Carnitine Guide. Available: http://www.hollandandbarrett.com/pages/categories.asp?cid=32&searchterm=carnitine&rdcnt=1. Last accessed 5th January 2012.

Hodge G. (2011, May). Total supplement guide. Mens Health. 3-48.

Jowko E, Ostaszewski P, Jank M, Sacharuk J, Zieniewicz A, Wilczak & Nissen S. (2001). Creatine and β-hydroxy-β-methylbutyrate (HMB) additively increase lean body mass and muscle strength during a weight-training program. Nutrition. 17(7): 558-566.

Kraemer WJ, Volek JS, Bush JA, Boetes M, Incledon T, Clark KL & Lynch JM. (1997). Creatine supplementation enhances muscular performance during high-intensity resistance exercise. Journal of American Dietary Association. 97(7): 765-770.

Kraemer WJ, Volek JS, Gomez AL, Ratamess NA & Gaynor P. (2001). L-carnitine supplementation favourably affects markers of recovery from exercise stress. American Journal of Physiology, Endocrinology and Metabolism. 282(2): E474-482.

McArdle WD, Katch FI & Katch VL (2007). Exercise physiology: energy, nutrition & human performance. London: Lippincott, Williams & Wilkins. 34-56.

Rebouche CJ & Paulson DJ. (1986) Carnitine metabolism and function in humans. Annual Review of Nutrition 6:41–66.

Smith, A. (2011). Creatine Guide. Available: http://www.bodybuilding.com/store/creatine.html. Last accessed 5th January 2012.

Tarnopolsky MA & MacLennan DP. (2000) Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. International Journal of Sport Nutrition and Exercise Metabolism. 10(4): 452-463.

Vukovich MD, Costill DL & Fink WJ. (1994). Carnitine supplementation: effect on muscle carnitine and glycogen content during exercise. Medicinal Science and Sports Exercise. 26(9): 1122-1129.

You May Also Find These Documents Helpful

  • Better Essays

    “The consumption of oral creatine monohydrate has become increasingly common among professional and amateur athletes” (Poortmans and Francaux, 2000). Creatine is a substance used by athletes and bodybuilders to increase the production of Adenosine Triphosphate (ATP), which gives them the energy they need to perform. In this experiment, creatine is added to water and its effects on Daphnia is tested. By observing the heart rate, one can determine if the creatine increases or decreases heart rate. Heart rate was chosen to be measured because one can then see how creatine affects the heart. If it is unhealthy for the Daphnia, it could potentially be unhealthy for humans. “Long-term safety of creatine supplementation has been questioned. This retrospective study was performed to examine markers related to health, the incidence of reported side effects and the perceived training benefits in athletes supplementing with creatine monohydrate” (Schilling et al. 2001).…

    • 1047 Words
    • 5 Pages
    Better Essays
  • Better Essays

    However, just because a supplement works one way for someone does not mean it works the same way for everyone. A question that is often asked is, “What effect does creatine have on muscle?” The Journal of the International Society of Sports Nutrition says that creatine “seems to produce positive effects on strength,…

    • 1485 Words
    • 6 Pages
    Better Essays
  • Good Essays

    Ergogenic Aids

    • 3584 Words
    • 15 Pages

    Ergogenic aids are substances or devices that enhance energy production, for use for recovery and provide athletes with a competitive advantage. Numerous ergogenic aids claim to enhance sports performance and are used by amateur and professional athletes. Approximately 50 percent of the general population has reported taking some form of dietary supplements, while 76 to 100 percent of athletes in some sports are reported to use them. Physicians can evaluate these products by examining four factors (method of action, available research, adverse effects, and legality) that will help them counsel patients. Common ergogenic aids include anabolic steroids, which increase muscle mass. These illegal supplements are associated with a number of serious adverse effects, some irreversible. Creatine modestly improves athletic performance and appears to be relatively safe. Dehydroepiandrosterone and androstenedione do not improve athletic performance but apparently have similar adverse effects as testosterone and are also banned by some sports organizations. Caffeine has mild benefits and side effects and is banned above certain levels. Products that combine caffeine with other stimulants (ephedrine) have been linked to fatal events. Protein and carbohydrate supplementation provides modest benefits with no major adverse effects.…

    • 3584 Words
    • 15 Pages
    Good Essays
  • Good Essays

    Creatine Research Paper

    • 467 Words
    • 2 Pages

    Creatine is one of the most popular supplements taken by athletes in order to boost available energy and to help build muscle strength. Unlike protein, creatine does not help to repair muscles or build muscle but allows the body to have more energy to work harder. Creatine is naturally found in the body and in foods such as seafood and red meats.1 Many studies have been conducted in order to scientifically show whether or not creatine really works. A common misconception is that creatine stimulates muscle growth. Creatine is not a steroid, however, it is a useful supplement that can help to increase muscle mass and boost athletic performance.…

    • 467 Words
    • 2 Pages
    Good Essays
  • Powerful Essays

    Supplements in Sports

    • 1797 Words
    • 8 Pages

    Creatine monohydrate, generally known as creatine is a popularly used supplement. Creatine occurs naturally in muscles, but many athletes or body builders take it to increase their strength and size. When using muscles, a chemical called ATP (adenosine tri-phosphate) is broken down into ADP (adenosine DI-phosphate) and an inorganic phosphate. The release of the phosphate is what gives the muscles energy. Creatine, whether, the naturally occurring, or from a bottle or jar, combines with phosphate and can restore ADP back to ATP. Theoretically, this means more energy. But it does not come without a price. The manufacturers and advertisers for Creatine tell…

    • 1797 Words
    • 8 Pages
    Powerful Essays
  • Good Essays

    Creatine is formed mainly in the liver from the methylation of glycocyamine by S-adenosyl methionine. It is then carried through blood to the other organs, muscle, and brain, where, through phosphorylation, it becomes the high-energy compound phosphocreatine. Creatine transformation to phosphocreatine is activates by creatine kinase; spontaneous formation of creatinine produces throughout the reaction. As shown in (fig. 15)…

    • 311 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Some athletes take anabolic steroids to increase their muscle mass and strength. The main anabolic steroid is testosterone, which promotes muscle building and responsible for facial hair and a deeper voice. Androstenedione is a hormone produced by the adrenal glands, ovaries and testes which allows athletes to train harder and recover quickly. Erythropoietin is a type of hormone used to treat anemia in people with severe kidney disease, but it is commonly used by endurance athletes (Mayo Clinic). Diuretics are drugs that change a body’s natural balance of fluids and salts and can lead to dehydration. Athletes mostly use diuretics to lose weight to compete in a lighter weight class (USADA). Creatine is a naturally occurring compound by one’s body that helps release energy. Creatine can benefit an athlete by producing small gains in short-term bursts of energy. Lastly, athletes use stimulants to stimulate the central nervous system and increase heart rate and blood pressure. Also, stimulants can improve endurance, reduce fatigue. Suppress appetite, and increase alertness and aggressiveness…

    • 760 Words
    • 4 Pages
    Good Essays
  • Better Essays

    Creatine is the one of the most popular supplements used in bodybuilding. According to some experts, “creatine adds bulk, rather than reducing it. It gives athletes extra…

    • 1018 Words
    • 5 Pages
    Better Essays
  • Good Essays

    Creatinine Lab

    • 1285 Words
    • 6 Pages

    3. "International Society of Sports Nutrition position stand: creatine supplementation and exercise". October 3, 2012.…

    • 1285 Words
    • 6 Pages
    Good Essays
  • Powerful Essays

    Creatine Case Study

    • 1866 Words
    • 8 Pages

    Creatine is a nitrogenous organic compound found in muscles that can be obtained in the diet through animal products (Butts, J., MD, Jacobs, B., DO, & Silvis, M., MD. 2017). Creatine is most often used to enhance sports performance and is more commonly used with athletes. Creatine has become the most popular supplement after the 1992 Olympic Games in Barcelona (Butts et al. 2017). Creatine is used to increase the amount of phosphocreatine in the muscle thus delaying fatigue. Phosphocreatine helps make ATP (adenine triphosphate) from ADP (adenine diphosphate) when energy demand is high. Research has shown that creatine has an augmenting effect in muscle strength and power especially when combined with a form of resistance training…

    • 1866 Words
    • 8 Pages
    Powerful Essays
  • Satisfactory Essays

    Gurinder Singh

    • 1158 Words
    • 5 Pages

    Im also taking 5mg or creatine with each protein shake (one in the morning, one after training)…

    • 1158 Words
    • 5 Pages
    Satisfactory Essays
  • Better Essays

    Phisical Education

    • 1455 Words
    • 6 Pages

    It is extremely important to analyze the products that are aimed at strengthening human health and shaping human bodies. As people should be aware of the genuine effect of different exercise devices, articles of health products, and food supplements, it is necessary to asses those products in accordance with certain criteria. In this respect, the abovementioned products can be considered more or less effective or those having negative effect on human health after a thorough examination. Thus, the products designed for improvement of health and physical condition should be effective and harmless for the category of people that is the target audience of this product.…

    • 1455 Words
    • 6 Pages
    Better Essays
  • Satisfactory Essays

    Steriods

    • 852 Words
    • 4 Pages

    Creatine. Creatine is a naturally occurring compound in the body that's also sold as an over-the-counter supplement. It's primarily used to enhance recovery after a workout and increase muscle mass and strength. Creatine is popular with athletes who participate in football, gymnastics, hockey and wrestling.…

    • 852 Words
    • 4 Pages
    Satisfactory Essays
  • Good Essays

    Despite the growing body of evidence of serious health risks associated with performance-enhancing drugs, the development and use of such substances have continued to increase. Rapid advances in sophisticated medical technology in recent decades have produced a wide variety of new drugs and procedures that athletes can use to gain an edge.…

    • 288 Words
    • 2 Pages
    Good Essays
  • Good Essays

    There are actually some supplements that can enhance the performance of athletes and football player and make them have a strength, many people consider that is a cheating because many types of those supplements are illegal and is just wasting of money. According to Young men’s health (2015) “Many supplements, such as anabolic steroids, are illegal because of the health risks. Many of these “legal” supplements substances have not been approved by the Food & Drug Administration (FDA), the office of our government that carefully researches the safety of products on the market.” Although some supplements are illegal and have health risks some athletes and football player are still taking those supplements, but the organization that are in control of sports and athletics like FIFA have done some rules to inhibit anyone who take steroids and supplements that are illegal to perform any sport and have made tests to detect any supplements or steroids. However some companies actually make illegal supplements and sell them in black market knowing that those supplements have health risks and are panned by FDA, but still people are buying them. Why you take supplements and waste money when you can balance your daily meals and work hard to get what you dream in a legal…

    • 1093 Words
    • 5 Pages
    Good Essays