Journal Information
Vol. 43. Issue 159.
Pages 142-151 (July 2008)
Vol. 43. Issue 159.
Pages 142-151 (July 2008)
Full text access
Athletic performance: muscle glycogen and protein intake
Visits
2598
This item has received
Article information
Abstract
Statistics
To achieve optimal athletic performance by controlling factors directly or indirectly associated with the intake, knowledge of how to control the metabolic processes associated with muscle glycogen and protein intake are highly important. Recovery of glycogen stores after exercise is a slow process, and complete recovery may take 24-48 h after exercise has ceased, depending on how much glycogen has been lost. The maximum rate of glycogen resynthesis occurs in the first 2 hours after the workout. The rate of muscle glycogen resynthesis could be accelerated through simultaneous intake of carbohydrate-proteins or carbohydrate-amino acids, effective combinations after the workout being sucrose or table sugar (1 g/kg) and whey protein (0.5 g/kg). Glycogen supercompensation or carbohydrate loading aims to raise glycogen storage above physiological levels to increase the duration of carbohydrate availability to exercising muscles, thus enhancing performance. The stored glycogen is accompanied by water, which increases muscle volume and definition, and consequently this strategy is frequently used by bodybuilding competitors. There are three supercompensation methods: the Astrand, Sherman/Costill and Fairchild/ Fournier, they have the same effectiveness but the least option is the quickest and easier way. Protein intake is essential for athletes but should account for no more than 15-20% of the daily calorie intake because protein loses its anabolic profile when consumed in quantities higher than this threshold. Thus, athletes aiming to acquire new muscle mass should increase total calorie intake by following a balanced diet and should not aim to increase calories from protein alone.