Sporting Supplements Should You Be Taking?

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produce enhanced phosphocreatine levels, an essential energy source for high-intensity exercise bouts performed in repeated succession.

Creatine is a natural substance already present in the body. An omnivorous diet will typically supply about 1,000mg of creatine a day, and synthesis of 1,000mg from the kidney and liver also occurs [3]. Degradation of creatine in the body occurs at about 2,000mg a day, thus matching intake, and a balance is achieved [4]. By taking supplements we can increase these muscle stores. Typically, a loading dose regime of 5,000mg four times a day for five days will increase muscle creatine concentration by circa 20%, though a wide range of variation exists [5]. After this 2,000-3,000mg a day will maintain these increased concentrations. Use should not just be limited to the traditional market of weight trainers or sprinters, but embraced by most exertive sports.

Indeed, creatine should be considered by all endurance athletes. Muscle glycogen, a major fuel in endurance activity increases proportionally to the extent of increase in muscle creatine levels. A five day loading phase increases glycogen levels on average by about 18% [6]. A useful approach is to supplement 5,000mg 4 times a day for periods of carbohydrate loading.

By Aidan Goggins BPharm, MSc Nutr Med, MPSI E

ntering your nearest gym or fitness store you will undoubtedly be greeted, if not overwhelmed, by the shelves crammed with products all advertised as the ultimate tool to achieving sporting and health dominance. As a pharmacist who specialises in sports performance and nutrition, I am always intrigued as to whether these claims are backed by hard science or are merely the elaborate creations of a design team solely obsessed with profits. With confusion abound, this article reviews those few products which meet the rigorous assessments of science and are worthy of consideration by those interested in maximising sporting performance.

Creatine Creatine is the most effective and established ergogenic nutritional supplement currently available in terms of increasing short term exercise capacity [1]. A review showed that by 2003, around 300 studies had examined creatine as a physical performance enhancer, and 70% showed significant results with the majority of the remaining 30% showing a non-significant positive trend [2]. Short term supplementation improves “maximal power/strength (5-15% -improvement), work performed during sets of maximal effort muscle contractions (5-15% -improvement), single-effort sprint performance (1-5% -improvement), and work performed during repetitive sprint performance (5-15% -improvement)” [2]. Benefits are conferred through increased skeletal muscle creatine content being utilised to

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Beta-Alanine Beta-Alanine is a precursor to the dipeptide carnosine, which acts as a buffering agent in the first line of defence to acid production in the skeletal muscle. Since muscle acidosis is a key contributor to the onset of fatigue during high-intensity exercise, any means of increasing muscle carnosine concentrations and thus our skeletal muscle buffering capacity, offers a much welcome ergogenic strategy by delaying the onset of fatigue [7]. This is especially true for exercise bouts lasting from one to four minutes, when lactic acid production peaks. A recent meta-analysis supports the value of incorporating beta-alanine to enhance performance outcome, finding that when supplemented at recommended doses a median performance improvement of 2.85% is observed [7]. Such a performance increase when applied to a suitable sporting event lasting around four minutes, such as a 1,500m run, would be expected to improve performance time by ~6 seconds. To put this in context, an improvement of this magnitude would have taken the second last placed finalist in the men’s 1,500m at the London 2012 Olympic Games to first place, gold medal position.

The standard dose for beta-alanine supplementation is between 2,000-5,000mg daily. Such doses of beta-alanine when taken commonly result in reports of paresthesia (tingling sensation). Whilst, this is not harmful, for many it is uncomfortable, and can be avoided by splitting the daily dose into amounts of less than 1,000mg beta- alanine at any one time.

Glutamine

Glutamine is the most abundant free amino acid in the body; comprising 40% of muscle amino acid levels and 20% in the plasma [8]. While primarily marketed at weightlifters to boost recovery and

The REPs Journal 2013;28(September):16-18