In older endurance athletes, glycogen (carbohydrate) storage per unit of muscle is lower than in similarly trained younger runners while glycogen usage per unit of energy expenditure is higher during endurance exercise. However, following regular endurance training, older individuals are able to increase muscle glycogen storage and restore glycogen stores post-exercise at rates similar to younger athletes.
The recommended carbohydrate intake for athletes (see Table below) is similar to that of the general population and therefore is similar for masters athletes since carbohydrate absorption and utilisation remains intact with aging. Thus, the older athlete should consume at least 55% of daily energy intake as carbohydrate obtained from a variety of food sources and the bulk of the carbohydrate-containing foods consumed should be those rich in complex carbohydrates and with a low glycemic index (see Chapter 16 of The Masters Athlete or http://www.glycemicindex.com ). A high percentage of this intake should be starchy carbohydrate (bread, cereals, rice, pasta, potato) that also provides protein, vitamin, mineral and fibre intake. However, too high a level of fibre (> 35 g/day) in these foods (e.g. wholegrain products, bran, wheat germ) may not be advantageous to older athletes due to the associated gastrointestinal discomfort or mineral imbalances that may arise as fibre can reduce the absorption of some minerals including calcium and iron.
Table: Recommended carbohydrate intake for athletes in a variety of events.
|Situations||Recommended Carbohydrate Intake|
|Fuelling up for an event, recovering from an event||7-10 gm/kg body weight/day|
|Rapid after-exercise recovery when less than 8 hrs between events||1 gm/kg body weight immediately after exercise, repeated after 2 hours<|
|Pre-event meal to increase carbohydrate availability prior to prolonged exercise||1-4 gm/kg body weight eaten 1-4 hours before exercise|
|Carbohydrate intake during moderate intensity or intermittent (e.g. team sports) exercise||0.5-1.0 gm/kg body weight/hour
|Regular Training Day|
|Daily recovery/fuel needs for an athlete doing less than 1 hour per day of low intensity exercise||5-7 gm/kg body weight/day|
|Daily recovery/fuel needs for an athlete doing 1-3 hours per day of moderate to high intensity exercise||7-10 gm/kg body weight/day|
|Daily recovery/fuel needs for an athlete doing extreme hours hour per day (e.g. Tour de France)||10-12 gm/kg body weight/day|