The World Keeps Running

Every runner is different. Not only do they have different requirements for energy and nutrients depending on body size and physique and on the distance of their event and training load, but in addition they have individual physiological and biochemical characteristics that shape their nutrient needs.

Each runner must therefore identify key nutritional goals, in terms of the requirement for energy, protein, carbohydrate, fat and all of the vitamins and minerals that are essential for health and performance.

Runners also like to make different food choices, based in part on cultural and lifestyle issues, but perhaps more on personal taste preferences.

Once nutritional goals are identified, each runner must therefore devise an eating strategy to ensure that suitable foods are eaten in appropriate amounts at the right times to meet those goals.

There is no simple formula to predict how much food a runner will need to eat to fulfil their energy needs. However, frequent training when allied with the energy demands of normal daily life, will require a higher intake of fuel.

Runners who are training to achieve weight loss or fat loss should seek guidance from a qualified sports nutritionist or doctor.

Protein

Protein plays an important role in the response to exercise. Amino acids from proteins form building blocks for the manufacture of new tissue including muscle, and the repair of old tissue.

They are also the building blocks for hormones and enzymes that regulate metabolism and other body functions. Protein provides a small source of fuel for the exercising muscle.

Some scientists have suggested that endurance and resistance-trained athletes in heavy training may have increased daily protein needs, though the evidence is not clear or universally accepted.

Recent studies have focused on the acute response to workouts of both endurance and resistance training.

Enhanced protein balance is a desirable goal of the recovery phase - to overturn the increased rates of protein breakdown that occur during exercise, and to promote muscle growth, repair and adaptation following the exercise stimulus.

These studies have found that eating a small amount of high-quality protein, combined with carbohydrate, enhances protein synthesis during the recovery period. There is some evidence that the response is enhanced when these nutrients are provided soon after exercise, or in the case of a resistance workout, perhaps before training.

In the light of this information, it appears sensible to focus on the total balance of the diet and the timing of protein-carbohydrate meals and snacks in relation to training, rather than on high protein intakes per se.

Protein rich foods - 10 g protein is provided by any of the following:

• 2 small eggs
• 300ml cow's milk
• 20g skim milk powder
• 30 g cheese
• 200g yoghurt
• 35-50g meat, fish or chicken
• 4 slices bread
• 90g breakfast cereal
• 2 cups cooked pasta or 3 cups rice
• 400ml soy milk
• 60g nuts or seeds
• 120g tofu or soy meat
• 150g legumes or lentils
• 200g baked beans
• 150ml fruit smoothie or liquid meal supplement

Carbohydrates

Carbohydrate provides an important, but relatively short-lived, supply of fuel for exercise that must be refilled each day from carbohydrate foods in the diet. Everyday eating and drinking plans for runners need to provide enough carbohydrate to fuel their training programmes and optimise the recovery of muscle glycogen stores between workouts.

General targets can be provided for carbohydrate needs, based on each individual's size and the demands of their training programme. For instance:

• Immediate recovery (within 0-4 hours) after fuel-depleting exercise: about 1g per kg of body weight per hour, consumed at frequent intervals;
• Daily recovery from a moderate duration/low intensity training session: 5-7 g per kg BW per day;
• Recovery from moderate-heavy endurance training or fuelling up for a distance event: 7-10g per kg BW per day.

Guidelines for carbohydrate should no longer be provided as a percentage of total dietary energy intake - for example 50% of energy intake. Such recommendations are not particularly "user-friendly" - most runners would be unable to choose meals based on such a target.

In addition, these guidelines are a poor way to ensure that the athlete meets a certain target for fuel intake. After all, a runner who eats 50% of a high energy intake from carbohydrate will eat much more carbohydrate than an athlete who eats 50% of a low energy intake from carbohydrate.

The new guidelines recommend daily amounts of carbohydrate in grams, on a sliding scale which changes with the athlete's size and the fuel costs of the training schedule. However, actual needs are specific to the individual athlete and need to be fine-tuned with consideration of the total energy needs and specific training goals.

Strategies for choosing carbohydrate foods and drinks and for optimising glycogen recovery:

• When the gap between training sessions is less than 8 hours (as when training twice daily), carbohydrate intake should start as soon as practicable after the first session to maximise the effective recovery time. Solid and liquid forms of carbohydrate are both suitable for recovery eating, but some choices may be more practical than others because of appetite, convenience or personal preferences;
• During longer recovery periods (24 hours), the pattern and timing of carbohydrate-rich meals and snacks do not appear to be critical, and can be organised according to what is practical and comfortable for each athlete. Given the amount of carbohydrate to be consumed, high carbohydrates foods will need to be spread out over the full 24 hours;
• It is valuable to choose nutrient-rich carbohydrates and to add other foods to recovery meals and snacks to provide a good source of protein and other nutrients. These nutrients may assist in other recovery processes, and in the case of protein, may promote additional glycogen recovery when carbohydrate intake is below targets or when frequent snacking is not possible;
• Adequate energy intake is also important for optimal glycogen recovery; the restrained eating practices of some athletes, particularly females, make it difficult to meet carbohydrate intake targets and to optimize glycogen storage from this intake.

Examples of nutrient-rich carbohydrate foods and meal combination:

• Breakfast cereal with milk
• Fruit with flavoured yoghurt
• Fruit smoothie or liquid meal supplement
• Sandwich with meat and salad filling
• Stir-fry with rice or noodles