The nutritional dietary procedure known as “carbohydrate loading” has been shown to substantially increase muscle glycogen levels. Increased muscle glycogen has a positive ergogenic effect on exercise performance in sporting events longer than 90 minutes in duration. However, the eficacy of the carbohydrate loading procedure is somewhat variable. This variability may be attributable to factors that inluence the ability of the muscle to supercompensate with glycogen. This article discusses those factors and aspects of the procedure that add to the variability in an attempt to improve the success of sportsmen and women (i.e., athletes) attempting to perform the carbohydrate loading procedure and improve their exercise performance.