Caffeine
Caffeine is the naturally occurring alkaloid and stimulant in coffee, tea, cocoa, gurana, cola and other plant product beverages. A strong cup of brewed coffee will give you about 100 milligrams of caffeine, instant coffee around 80 milligrams, often less, and tea down around the 40 milligrams. It varies from product to product and how you prepare the drink.
Caffeine supplementation has been shown to benefit some endurance athletes like marathoners taken before an event or training. Originally this was though to be related to energy availability, but more recently research has suggested that it may be more to do with delaying a condition called ‘central fatigue’, where the brain does not pass signals to the working muscles efficiently, which results in a general tiredness. Caffeine may slow or prevent this from occurring.
Although caffeine has also helped in higher intensity training such as shorter track events, its benefits for weight training are not well established and similar stimulants such as ephedra are sometimes used. The safety of ephedra is under review. Even so, ‘central fatigue’ is an issue long debated in the weight training community, so caffeine could well be a useful ergogenic aid for weight lifters. The strategy would be to include caffeine in a pre-workout drink or supplement.
Safety. In general health terms, most medical opinion is that up to three cups of coffee a day are not harmful, and may even have some benefits, although some people respond to the stimulant properties with more problems than others. Heart palpitations and restlessness are experienced by some caffeine drinkers. In pregnancy, one or two cups each day are thought to be without harm for the fetus.
How much. The amount used by athletes has been in the range 3-6 milligrams/kilogram body weight (or about 1.5-3 grams/pound body weight). For a 180 pound (82 kilo) person, that’s around 300-400 milligrams caffeine average. That’s quite a bit of caffeine, so in my view, a couple of cups of coffee or equivalent taken before a session should be enough to get you going. Some coffee houses sell double shots in big mugs with around 300 milligrams in one cup.
Glucosamine
Contrary to the sound of the name, glucosamine is not a glucose replacement drink but a naturally occurring compound that has received publicity and wide support as a supplement for the relief of arthritis pain and possible prevention of further joint damage. Glucosamine has been popular with sports people of all types, including weight trainers, particularly for knee arthritis and pain.
While some evidence exists that glucosamine works to relieve pain, the latest evaluation by medical experts suggests that it does not work as well as once thought. Here is what the prestigious Cochrane Library Report had to say:
It was shown in a previous Cochrane review that glucosamine taken for 6 weeks decreases pain and improves function (physical ability) in people with osteoarthritis. When compared to the previous review, this review which analyzes newer studies and more high quality studies, shows there is "platinum" level evidence that pain does not improve as much when taking glucosamine for 2 to 3 months. Depending on the scale used to measure function (physical ability), function may not improve at all or as much.
Glucosamine seems to be safe to use.
Glutamine, HMB and Beta-alanine
Glutamine and beta-alanine are amino acids and HMB, beta-hydroxy-beta-methylbutyrate, is a byproduct of leucine, another amino acid. Promoting individual amino acids, the building blocks of protein, to enhance performance in the strength sports has been a particular focus of supplement manufacturers over the years. To date, the evidence for any advantage has been mixed and mostly unimpressive.
Glutamine has not really lived up to its early hype as an immune system protector and muscle enhancer. It’s probably not going to provide protection of the immune system in heavy exercisers beyond what can be achieved by ensuring adequate carbohydrate intake, which also protects immunity. Anabolic benefits from glutamine alone have not been proven. I wouldn’t spend money on this one.
HMB supplementation is claimed to build muscle size and strength and promote fat loss in conjunction with a strength program. Studies of HMB have shown some benefit to strength athletes in building muscle bulk but the benefits are relatively small and the cost of HMB is high. The effective dose seems to be 3 grams/day divided into 1 gram three times a day. Probably not worth taking.
Beta-alanine is the new guy on the block and has not been evaluated sufficiently in my view. It may provide some advantage in high intensity sports like weight training but it’s much too early to know that it does. Some early studies are flawed. Save your money or try creatine instead.
Other Amino Acids
Arginine, and leucine, valine and isoleucine, the branched-chain amino acids, are also promoted and sold as beneficial supplements for strength trainers and athletes. As individual products there is no evidence of benefit beyond their role in complete proteins. Leucine may be worth watching for possible benefit with further evaluation.
Summing Up Supplements
If you are a ranked athlete, don't put anything in your mouth that could fail you in drug testing. For amateurs, don't believe every thing you read in the muscle mags or on the internet. Much independent testing is required to verify the value and safety of supplements.
References
Maughan RJ, King DS, Lea T. Dietary supplements. J Sports Sci. 2004 Jan;22(1):95-113.
Kreider RB. Dietary supplements and the promotion of muscle growth with resistance exercise. Sports Med. 1999 Feb;27(2):97-110.
Kerksick CM, Rasmussen CJ, Lancaster SL, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. 2006 Aug;20(3):643-53.
Update of Cochrane Database Syst Rev. 2001;(1):CD002946. Glucosamine therapy for treating osteoarthritis. Cochrane Database Syst Rev. 2005 Apr 18;(2):CD002946.
AIS Sports Nutrition - AIS Sports Supplement Program 2007.
www.ais.org.au/nutrition/Supplements.asp
