Meeting energy (Calories / kilojoules) needs is the first nutritional priority for all athletes. A small energy deficit between energy intake and output can be tolerated for body fat loss. However, long term energy deficit or too rapid a weight loss, will lead to a loss of muscle mass and thus loss of strength and endurance, immune system problems, menstrual difficulties in females, and most importantly, lead to decreases in training and competitive performance.
An age-related decrease in daily energy expenditure, at least in non-athletes, is primarily due to both age-related decreases in muscle mass and decreases in physical activity levels. Current recommended daily intakes for moderately-active men and women between 19 and 50 years of age have been established at 2,900 (12,200 kilojoules) and 2,200 (9,200 kilojoules) Calories per day, respectively.
Athletes of all ages require energy to maintain normal bodily functioning and provide fuel for working muscles when training or competing. Training has been shown to increase energy requirements and help maintain muscle mass in healthy, previously sedentary aging individuals. A number of studies examining the energy intakes of older athletes suggest that older athletes undertaking regular physical training have higher energy intakes than those of age-matched inactive but healthy people. Furthermore, a number of these studies have also found that the energy intakes of these older athletes are higher than those suggested for their respective age groups or gender. For example, energy intakes ranging between 10,336 kJ/day and 11,549 kJ/day have been observed for older (55-75 years) male endurance athletes with 8,663 kJ/day intakes having been observed in 65-84 year old female endurance athletes undertaking physical training of at least one hour per day.
In general, the following percentages of daily energy intake (Calories or kilojoules) should be taken in by athletes both young and old:
- Carbohydrates 55-58%
- Fat 25-30%
- Protein 12-15%
Carbohydrate, fat and protein intakes are essential for meeting not only the energy requirements of masters athletes, but to ensure normal bodily functioning and health through the associated intake of fibre, vitamins and minerals.