Expert: Miss Sylvia Lam - Registered Dietitian and Chairlady of Hong Kong Dietitians Association
It is important to eat a healthy, balanced diet, especially for runners who have just started their training program – the sudden increase in exercise would easily lead to an increase in appetite and increased intake of foods. To achieve a well-balanced diet, runners should be careful with the proportions of intake of carbohydrates, protein and fat:
- 55-60% of energy should come from complex carbohydrates, which help store glycogen in muscles and liver.
- Keep fat intake less than 30% (or even 20-25%) of daily energy intake. This helps control weight.Protein intake should be around 15% of daily energy intake.
- Lean protein sources (lean meat, skinless chicken, fish, tofu, etc) are preferred.
- Eat plenty of fruits and vegetables for vitamins and minerals.
Long distance running is a form of endurance sports. Runners should choose slowly digestible carbohydrates like brown rice, red cargo rice, oatmeal, whole-wheat bread, whole-wheat pasta and cereal. Practice hydration and glucose replenishment before, during and after running with sports drinks (1-2 hours before: 500ml fluid; during: 500ml sports drink per hour; after: estimate fluid loss by weight and multiply by 125-150%) and sports gels.
Weight control is also a key if you are to participate in a long distance running competition. For overweight runners, try to lose 5% in 3-4 months before race by practicing low fat diet. This will allow you to run a personal best.
For 10km race runners, additional carbohydrate intake before race is not necessary. A carbohydrate-rich meal two hours before race will be sufficient to provide the energy required. For half marathon and marathon runners, their carbohydrate intake should be increased according to their body weight three days before race. A runner will need 7-10g of carbohydrates per kg of body weight to achieve carbohydrate loading. In general, based on a body weight of 50 kg, this means one should 7-10 bowls of rice or an equivalent amount of carbohydrates. You could also choose sports drink, fruit juice or desserts to supplement your diet.