GROWLING DOG

Creatine is a compound found in skeletal muscle that supports power energy production. It is stored in the muscle tissue in the form of creatine and creatine phosphate (CP) and plays an important role in exercise metabolism by providing a limited, but rapidly accessible source of fuel for the 'phosphocreatine energy system'. This system is utilised during short duration, high intensity exercise involving short, sharp & powerful movement patterns such as sprinting, jumping, lifting, throwing or tackling. Adenosine triphosphate (ATP) which is broken down into adenosine diphosphate (ADP) provides the energy for all muscle contractions. The role of CP is to facilitate rapid ATP regeneration as quickly as it is broken down to maintain maximal power output. However this can only be sustained for a very brief time (5-10 seconds) before CP stores are depleted and other energy systems with reduced power output have to be recruited to support the exercise bout or activity. Hence, fatigue that occurs during very high intensity exercise is associated with the depletion of muscle CP.

The body obtains creatine from dietary sources (animal proteins such as meat, poultry, eggs & fish) and internal biochemical synthesis from the amino acids L-Arginine, L-Methionine & glycine within the kidneys, liver & pancreas. The average diet incorporating animal proteins will normally provide around 1-2g of creatine daily. Extensive sports science research has shown that it is also possible to further increase the level of stored creatine within the muscle cell with creatine supplementation. In 1992, Harris et. al. demonstrated that oral creatine supplementation could increase muscle creatine levels by ~20%. Hence, specific dose protocols known as 'Creatine Loading' & 'Maintenance' programs have been developed in line with the scientific evidence supporting creatine supplementation.

Creatine Loading: Take 20-30g of creatine per day (in divided 5g doses over the day) for 5-7 days. It is best taken during meals & snacks as carbohydrate (~70g) supports creatine uptake through the stimulatory effect of insulin. The muscle cell has a creatine threshold or saturation point and typically creatine loading increases total creatine & CP levels by ~25% above normal levels. Once loaded muscle creatine content will remain elevated for 4-6 weeks before eventual degradation to pre-supplementation levels. Hence, to maintain maximum muscle creatine stores, it is advised to take a lower, daily maintenance dose.

Creatine Maintenance: Take 2-3g of creatine per day

Harris, R.C., Söderlund K. & Hultman E. (1992) 'Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clinical Science; Vol. 83:367-374.