Beneficial Marketed Supplements
A number of products have shown benefits in specific sports or events following well-controlled scientific trials. It is widely known that not all people will respond positively to these supplements. Indeed, some individuals may respond negatively to them. Thus, it is essential to try the supplement prior to using them in competition as well as ensuring they are used to the scientifically-proven methods (e.g. dosage, timing) suggested.
Creatine is a muscle fuel derived from amino acids and stored primarily in muscle. Most of it is stored as creatine phosphate, a substance used as a fuel for explosive efforts lasting 5-10 seconds such as a 100m sprint on the track, the start and first 25m of a swim sprint, or sprints in a team game such as hockey or soccer. The body turns over about 1-2 grams of creatine a day with this amount replaced naturally by eating animal products such as meat and eggs, making vegetarians more prone to benefit from supplementation. Additional creatine needs are made in the liver from amino acids and then transported to the muscles for uptake and use. Research suggests the amount of creatine in the body declines with aging, at least in non-athletes.
Research has shown that 70% of people who load their bodies with creatine monohydrate can increase their muscle stores of creatine phosphate, thus increasing their capacity for speed and power. The correct loading method involves 4-5 doses a day for five days with 5 grams/dose, thus giving a total of 20-25 grams/day leading into a major competition or when trying to put on muscle mass. Once the supplementation stops, it appears the muscle levels of creatine return to normal after 4-5 weeks. Thus, once loaded, a maintenance dose of 1-2 grams/day appears enough to maintain muscle creatine levels. An alternative loading method is to use 3 grams/day for 28 days.
Recent research has shown that taking creatine with 75-100 grams of carbohydrate (2 bananas, 4 slices of bread, litre of sports drink) enhances creatine uptake. Creatine appears to benefit repeated 6-30 second efforts with 20 second to 5 minute recoveries in between. The benefit appears to be gained by enhancing the resynthesis of the fuel used in these efforts – creatine phosphate. Thus, players of team or racquet sports, weight trainers, or sprinters doing interval training appear to gain the greatest performance benefits of creatine monohydrate loading. It does NOT appear to benefit one-off sprint efforts or endurance performance, despite what the magazines or websites might say. In some sports that are weight-sensitive such as rowing, rock-climbing, or cycling, creatine’s use is only recommended if the weight gains (around 1 kg during loading) are not at the expense of power.
Other benefits commonly seen with creatine supplementation are increases in muscle mass and strength. Given that aging leads to decreases in muscle mass, muscle strength and sports performance, there has been a lot of research on the possible benefits of creatine monohydrate supplementation on older people, including aging athletes. In summary, the studies on older non-athletes (70 years of age) suggest that older people cannot increase their creatine stores as much as younger people after creatine supplementation. However, creatine supplementation at 0.3 gram/kg body weight/day for a week appears to lead to increased muscle mass, muscle mass, strength, and the ability to repeatedly do maximum efforts. However, the improvements are less than those observed in younger people.
To date, few studies have examined the effects of creatine monohydrate supplementation on performance in older athletes. French sport scientists compared the maximum cycling power and repeated cycling capacity of 14 older cyclists (66±1.2 years) with those of 14 inactive men (70.1±1.2 years) and 14 young (26±1.2 years) non-athletes. Before and after 5 days of creatine loading (3 x 5 grams/day), each person did a 5 x 10-second all out sprints with 60-seconds between efforts. While the young and older non-athlete groups improved their performances, the older athletes showed no improvement in performance. While this might suggest older athletes may not benefit from creatine supplementation, it remains to be seen whether an increased dose similar to that used by younger athletes (20-25 grams/day) would increase older athletes repeated sprint performance.
There has been much speculation over negative side effects of creatine loading. Anecdotally, nausea, gut upsets, headaches, muscle cramps, and muscle strains have been linked to its use. However, research has shown no liver, muscle or kidney dysfunction when healthy people consume creatine to the above recommended doses. Masters athletes with kidney problems may be advised to seek medical advice on loading with creatine or use the 28 day, 3 grams/day loading method that will not overload the kidneys as much as the 20-25 gram/day method. Because creatine uptake by muscles requires water, dehydration may be a problem such that increased fluid uptake is recommended during loading.
Caffeine is a naturally occurring stimulant found in coffee, tea, chocolate and cola drinks that provide between 30-100 mg/serve. Some non-prescription medications such as No-Doz can provide between 100-200 mg of caffeine /tablet while a Starbucks Grande Coffee has 330 mg.
Caffeine has been well-documented by research to have the following benefits:
- Central nervous stimulant – increases perception and reduces feeling of effort and pain
- Improved strength and power – by stimulating the release and uptake of calcium by muscle fibres that enhances the force of muscle contraction
- Improved repeat sprint ability
- Increased endurance as measured by time to exhaustion – by increasing the use of fats as a fuel and thus sparing the stored carbohydrate (glycogen), particularly during the first 15-20 minutes.
Caffeine doses of between 3-6 mg/kg (1.4-2.7 mg/lb) of body weight taken 30-60 minutes prior to performance appear to enhance speed and power performance as well as repeat sprint performance seen in team sports.
Essential Amino Acids (EAAs)
There are nine essential amino acids the body cannot make itself and therefore must be consumed in the diet. Research has shown that EAAs have no ‘performance’ benefits but that using them before and after exercise increases the uptake of amino acids, thus enhancing muscle recovery after high intensity training. Researchers suggest taking 15 grams before training and no more than 20 grams after training with the effects enhanced by combining the EAAs with carbohydrate before training. Current recommendations are to consume 3-20 grams per day in combination with carbohydrate 30 minutes before training and a similar dose within 60 minutes of finishing training.
Branched-Chain Amino Acids (BCAAs)
The essential (body does not make them so must be found in the diet) amino acids leucine, isoleucine, and valine are collectively known as branched-chain amino acids and make up about 30% of the total muscle protein content. They are found in whey protein, milk, meat, fish and eggs and other quality protein sources. They are in high demand during endurance exercise as an energy source and are fundamental to repairing and building muscles after hard training.
Research has consistently shown that supplementing with BCAAs before, during and after hard training has reduced muscle breakdown, enhanced muscle repair and thus enhanced recovery time, and lead to improved mental performance during marathon runs. While supplementing with BCAAs does not directly benefit performance, the above benefits have been shown with dosages ranging between 9-15 gram total dose during exercise lasting 2 hours or more and 12 grams daily for 2 weeks may assist in enhancing recovery and reducing muscle damage following hard exercise.
HMB is a naturally-occurring product within the body produced from the essential amino acid leucine. HMB has been suggested to improve strength and muscle mass and thus improving speed, strength and power performance. It has also been suggested to spare the breakdown of muscle protein and speed recovery from hard training. However, the studies that have shown these benefits have used older and younger non-athletes and dosages of 3-6 grams per day. In athletes, the benefits suggested on these dosages have not been shown. Some researchers suggest that a higher dosage may have benefits in athletes. However, the consensus of research suggests that older athletes just starting out or increasing their training load and who want to lessen the associated muscle soreness may benefit on using 3 grams per day for 3-5 weeks when starting a new program.
Very recent sports nutrition research has focussed on this substance (found in the diet in chicken and turkey) being used as a supplement. However, alanine itself does not have a performance-enhancing effect; it is alanine’s effect on a protein called carnosine that affects performance. Scientists have shown an increase of 64% in muscle carnosine after four weeks of supplementing with 4-6 grams per day of beta-alanine. Carnosine is found mainly in fast-twitch muscle where it helps buffer the effect of lactic acid produced during anaerobic work, thus theoretically enhancing team sport performance.