The term ‘Carbo-loading’ is referred to as the increased food consumption of carbohydrates in preparation to endurance races, events or training sessions. The theory behind carbo-loading is to maximise the storage of glycogen within the muscles to ensure there is enough fuel in the body to allow successful completion of races and events. Glycogen is the fuel which helps to generate energy during long distance events to help maximise performance.
The strategy is commonly seen in marathon runners, cyclists and other athletes normally lasting greater than 90 minutes. Glycogen stores can usually sustain sufficient energy expenditure and energy supply for up to 90 minutes until form and performance decline. This phase of the race or event is commonly known as ‘hitting the wall’.
Sports drinks and gels that are consumed during races or other endurance events can assist in prolonging energy levels and maintaining sufficient levels of glycogen to allow performance to continue to a high level. However, to maximise performance, research suggests that it is advisable to carbo-load in advance to give the body a ‘full tank of fuel’ to gain the greatest benefits and to reap the rewards.
How does it work?
In the early years, athletes were advised to temporarily reduce their carbohydrate intake and deplete their energy levels until three days prior to the event. These three days would then be used to top up their energy stores with as much glycogen as possible within muscle tissue by overloading the diet with carbohydrates. However, researchers suggested that this process may be detrimental to the athlete and scientists advised against the initial depletion phase. Instead, the latter carbo-loading phase has been deemed as sufficient.
Latest research tends to vary on specific advice on how early to start carbo-loading but most people begin the process between three and five days prior to the event.
The majority of the population require approximately 5-7g of carbohydrate per kilogram of body weight or 60% of the daily calorie intake from carbohydrates. This equates to approximately 1500kcal and 1800kcal from carbohydrate per day for the average woman and man respectively.
The carbo-loading period recommends increasing the carbohydrate consumption to 8-10g per kilogram of body weight (Anita Bean, The Complete Guide to Sports Nutrition; A C & Black, 2003). Guidelines show that for a 70kg runner, a consumption of between 560g and 700g of carbohydrate per day is sufficient. These figures are based on the fact that each gram of carbohydrate equates to four calories. Therefore, during the carbo-loading period for a 70kg runner, 2800kcal carbohydrates per day would be recommended.
Fitness instructors and nutritionists would recommend increasing the carbohydrate intake progressively over five or six smaller meals during the day rather than heavily overindulging with three meals only.
Examples of recommended foods high in carbohydrates include wholegrain bread, cereals, pasta, brown rice and potatoes.
In conjunction with carbo-loading, it is crucial to maintain a high intake of protein as part of the diet. Protein will help to enhance energy levels and reduce the digestion rate of carbohydrates allowing a controlled and efficient release of energy.
Please feel free to contact the Manchester G4 Clinic to speak to a member of the team for any questions that you may have.