It would seem that everyone is looking to squeeze the most out of their training investment and as a result, the supplement industry has globally become a multi-billion dollar industry. There are however very few legal ergogenic (performance enhancing) supplements on the market whose benefits are proven and whose negative side effects are minimal. A large majority of the supplements on the market are either dangerous e.g.. Ephedrine or have absolutely no benefit at all on performance e.g. orthonine, arginine. In this article we have chosen to highlight three products, which have proven performance-enhancing properties, these include creatine, caffeine and carbohydrates.
A product that has been repeatedly shown to improve performance in power-type sports and especially those that involve interval training is creatine. Creatine is a combination of three different amino acids and is produced naturally in the body, the vast majority being stored in skeletal muscle as creatine phosphate. Creatine phosphate is able to maintain muscle ATP (a high energy molecule and the energy "currency" of the body) levels in muscle by "donating" its phosphate to ADP (a lower energy molecule) thus allowing for an increased reserve of instantaneous energy to be used during very high intensity exercise. For example, creatine is likely to benefit high intensity exercise such as weight/power training and repeated sprints/interval training but not single sprint events lasting shorter than 90 seconds and endurance competition. The American diet supplies about 1 gram of creatine, which is found in red meat and some fish species (mackerel), but studies have shown that supplementing with 20 grams of creatine monophosphate for six days may increase muscle creatine levels by 20%. The recommended dosage is to take a "loading" dose of approximately 20 grams (4 teaspoons) a day for 5 days; thereafter a "maintenance" dose of 5-10 grams is required.
In addition, it is recommended that the individual take the supplement dissolved in a drink of high carbohydrate content (about 2 hours before exercise) as this causes an insulin "spike" which assists in muscle creatine uptake by more than half. It is proposed however that not all individuals respond to the use of creatine equally - some respond well by being able to store the additional quantities while others do not seem able to do the same. Lastly, it is suspected that the use of creatine is relatively safe although the long-term health risks of high dose supplementation are unknown. The only drawbacks known at this time is that it may cause stomach upset if not dissolved properly and individuals with existing kidney disease should not use it. Competing athletes are encouraged to use only high quality products from an established supplier, as some manufacturers have deliberately spiked their products with illegal performance enhancing substances and steroid precursors such as nandrolone, while other products may be contaminated with toxic metals.
There is a large body of evidence to indicate that caffeine use even at levels below that allowed during Olympic competition (>12 mg/ml) produces several ergogenic effects. Studies involving cyclists performing at a fixed intensity have demonstrated an increased time to fatigue ranging from 20-50% when using the product. Also, caffeine improves performance during all-out efforts lasting 4-5 minutes and during repeated bouts of exercise such as interval training. Caffeine has also been demonstrated to increase the maximum force that can be sustained during a maximal voluntary contraction (MVC) of a muscle and that the duration of sustaining an isometric contraction at 50% MVC increases on the order of 28%. It is proposed that this effect is due to increased skeletal muscle recruitment by the motor cortex of the brain, and that caffeine may also decrease the perception of effort allowing for more relative work to be performed. Thus caffeine may improve performance in a strength training routine. Other proposed methods of its operation is that it reduces fatigue and increases alertness and well-being which may be helpful during events of extreme duration such as ultra marathons where staying awake plays a crucial role in performance results. Some evidence seems to indicate a glycogen sparing effect associated with the use of caffeine, however its metabolic effects has not been substantiated.
Furthermore, it has been demonstrated that caffeine does not increase urine production during exercise, but does so at rest. Popular sources of caffeine are coffee (50-100 mg/cup), cola drinks (50mg/375 ml can) and over the counter medications (100-200 mg/tablet). It is possible that the tablet source may produce more ergogenic effects on exercise as it is suspected that other chemicals found in coffee may interfere with caffeine's operation. Caffeine should not be consumed in association with creatine as there is some evidence to indicate that the former prevents the latter's absorption.
Although one may not think of it as a supplement in the true sense of the word, as mentioned previously in other articles and tips on this website, the use of carbohydrate during and immediately after exercise has demonstrated various ergogenic effects. Research has indicated that hypoglycemia (low blood sugar) can be a significant cause of fatigue and premature termination during prolonged exercise events. Consuming carbohydrates during a race will not necessarily allow an individual to perform better, but it will increase the time to fatigue should they not have enough liver glycogen (stored glucose) to maintain blood sugar levels for the duration. In a previous article on the lactate threshold/turnpoint we discussed the fact that muscle glycogen is committed to be used in its cell of storage. The liver however is capable of releasing its glycogen stores as glucose into the blood stream to maintain blood sugar levels. The liver glycogen reserves however are limited - only about 100 grams, whereas the skeletal muscle is able to store about 500 grams. It is estimated that during prolonged exercise events such as marathons, the rate of blood glucose usage is 1.0 gram per minute or 60 grams per hour. So assuming a non-carbohydrate loaded participant enters such a competition even with full liver glycogen stores, they would only be able to maintain blood sugar levels for about an hour and a three quarters before hypoglycemia would begin to set in.
Regular carbohydrate ingestion during the race will help the participant to maintain normal blood sugar levels and avoid fatigue and the early termination associated with hypoglycemia. Another associated benefit of carbohydrate ingestion during exercise is its protein sparing effect. During aerobic or endurance type exercise, as muscle and liver glycogen levels begin to fall, protein (source of amino acids) from muscle stores is increasingly broken down to help replenish blood sugar levels through gluconeogenesis (the production of glucose). With the maintenance of blood sugar from ingested carbohydrates, less protein and lean tissue mass is sacrificed. In addition it is suspected, although still questionable at this point that carbohydrate consumption may prevent central or neural fatigue by limiting the amount of free tryptophan in the blood. Tryptophan is an amino acid from which the substance serotonin (a substance which induces sleepiness and fatigue in the brain) is made. Carbohydrate ingestion in combination with protein immediately after intense exercise has been demonstrated to increase protein/muscle synthesis and increase muscle glycogen stores (glycogenesis). It is likely that the increased protein synthesis is mediated by increased quantities of a hormone known as IGF-1 (Insulin-like Growth Factor-1). Lastly, as mentioned earlier carbohydrate assists indirectly in the transport of creatine monophosphate into skeletal muscle, thus increasing reserves of creatine phoshphate.
In conclusion, there are some supplements that have proven ergogenic properties and are presently considered safe. It is not advisable however to consume all of these supplements together since one product may have negating effects on the other. Unfortunately, the marketing of supplements often far exceeds the potential benefits to be gained. The consumer should carefully consider the energy and metabolic demands of their sport/event or alternatively consult the services of an experienced exercise professional. This will allow the individual to choose the supplement that best suits their needs and avoid spending money on potentially useless products or risking their health or competition status.
David Petersen is a Personal Trainer/Certified Strength and Conditioning Specialist and the owner and founder of B.O.S.S. Fitness Inc. based in Oldsmar, Florida. More articles and information can be found at http://www.bossfitness.com
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