What and when to eat to optimise sports performance?
What and when to eat to optimise sports performance?
Sometimes in sports there is a focus on macronutrients (proteins, carbohydrates and fats) but little emphasise on vitamins and minerals but these are essential! For example iron is an essential component of haemoglobin which transports oxygen to your body cells, magnesium acts in the enzymatic conversion of intermediate substances during ATP (energy) production, and B vitamins such as thiamine (B1), riboflavin (B2), and niacin (B3) are essential in generating large amounts of energy in the cell! So without having these vitamins and minerals present in adequate amounts you will find it hard to reach optimum performance and will likely fatique early.
The best way to get all of these vitamins and minerals is through a good diet. Improving your diet a week or two before a competition is beneficial but the greater benefit is seen in those who have integrated a good healthy eating plan during the year!
What is a good healthy eating plan?
A healthy eating plan includes plenty of vegetables (a mixture of dark green leafy vegetable, purple, yellow and orange vegetables); adding a few lettuce leaves and a slice of tomato to a sandwich is just not enough! Ideally you should be having 4-5 portions of vegetables a day (2 cups of salad leaves or 1 cup of carrots/peppers/tomatoes is considered one normal portion size). One to three portions of fruit per day is sufficient for most people (depending on energy requirements). Remember vegetables and fruit contribute to your overall carbohydrate intake!
The next thing is to ensure any grains you eat are wholegrain. These provide a range of B vitamins and plenty of fiber to support good bowel movement! My favourites are quinoa (keen wah) which has a good range of amino acids, oats and wholegrain rice. For anyone who follows a fat-adapted diet plan please read my previous blog on fat adaptation: Getting fat adapted
Good sources of protein rich foods should be included in every meal. Great protein sources are beef steak, lamb chops, chicken breast, tuna steaks, milk and eggs. Salmon and other oily fish also contain great sources of omega 3 which helps to dampen down inflammation in the body. Omega 3 is particularly important in regard to immunity and recovery from injury. There are also good non-animal sources of protein such as chick peas (hummus dips), kidney beans, lentils, nuts and seeds. The beauty about nuts and seeds is that they are convenient and contain an excellent range of minerals such as magnesium, calcium, selenium and zinc. Including some brazil nuts, cashews nuts, hazelnuts, pumpkin seeds and sesame seeds is a great way of upping your protein intake and getting some healthy polyunsaturated fats into the diet. Protein requirement for the general population is 0.8 grams (g) per kilogram (kg) of body weight but depending on your sport and body composition you may need 1 to 2 g per kg of body weight.1,2 For a 75 kg individual this equates to 60 g (general population) and 75 g up to 150 g of protein for athletes. To give you an idea; a portion of meat will provide about 25-30g of protein and an egg around 8g of protein. From my experience most people easily meet their protein requirements through diet alone. Unless you are lifting heavy weights and there is continued hypertrophy then you are unlikely to require any extra protein. Excess protein which is not used by muscle cells or for other functions will instead be used for energy, ultimately sparing fat stores; which is not good for anyone trying to reduce their body fat percentage!
In regard to fat, don’t be afraid to include some olive oil (for low heat) or coconut oil/macadamia nut oil (for high heat) at your main meals. Fats are also important for the structure of our cell membranes and hormone production but a low fat meal is best close to exercise.
What should I eat and drink before exercise/training/match/game?
This will all depend on whether you are elite, well-trained or a recreational sports person. Some people eat like they are an elite athlete but are not training or competing at a high level, and therefore may not need extra carbohydrate, protein shakes or supplements etc.
Before exercise you should eat to satisfy hunger and ensure glycogen is replenished. If you had a hard training session the evening before and are training again the next day you may need to have some extra carbohydrate on board to ensure your glycogen stores are topped up. Glycogen is the storage form of carbohydrate in your muscle and liver. We have a limited capacity to store glycogen but the more we have stored then the greater ability there is to use it as a quick fuel sources during exercise. Remember any carbohydrate that is not converted to glycogen can then be stored as fat so it’s important to find your sweet spot (eating enough carbohydrates to replenish glycogen but not too much to increase fat storage).
Individuals with greater muscle mass have a greater ability to store glycogen. For a big match or competition you may wish to try carbohydrate loading. This is where you taper training for a few days before a game and eat a large amount of low fiber carbohydrates (to maximise the amount of carbohydrate consume). However, many people do not tolerate large amounts of carbohydrate and the gastrointestinal symptoms may offset the extra glycogen stored!
The focus before exercise is on carbohydrates but including some branched chain amino acids (BCAA), may help improve time to exhaustion, maximise power output and stimulate protein synthesis after exercise.2,3 BCAAs include three amino acids; isoleucine, leucine and valine. Good sources of these are meat, dairy, egg whites, nuts and seeds.
Another important aspect is to leave time for digestion. If you are eating 3 to 4 hours before exercise then you can have a normal balance meal e.g. sweet potato with some green beans, peppers and a tuna steak. Or if you are going straight from work to training (around 1 to 2 hours before exercise) then it is better to eat something that can be easily digested such as some fruit, nuts and yoghurt. The higher the intensity the exercise is then the greater time you need to allow for digestion. Timing is also quiet individual, some people feel better eating at least 3 hours before training and others can tolerate food up to 1 hour before exercise.
There should be plenty of water on board before exercise and ideally only water should be consumed within an hour before exercise. Having a sugary drink may cause a spike in blood sugar followed by a surge in insulin release that rapidly lowers blood sugars (in people who are sensitive to sugar). You do not want to risk having low blood sugar just before you start training or a match! But in the last 10 minutes before exercise it is ok to drink a sports drink for example as there is not enough time for the body to pump insulin into the blood and by the time exercise starts your body has downregulated its insulin release!
2-3% body water loss can reduce performance but be aware that excess can cause low sodium levels (hyponatremia). It is important to sip water throughout the day and not gulp a liter or two just before training!
Table 1: Pre-exercise nutrition
| Time before exercise | Example |
| 1 hour or less | 500 ml water (no food), a sports drink or homemade sports drink 10 minutes before starting exercise |
| 2 hours | Smoothie made from yoghurt and low fiber fruit such as banana, peaches, honeydew and watermelon. Fibrous fruits that are best avoided too close to exercise include apples, berries, dates, figs, grapes, pears, mango and pineapple (but this will depend on personal tolerance level) |
| 3 to 4 hours | Quinoa with broccoli, cauliflower, cod fillet with a tomato based sauce |
What should I eat and drink during exercise/training/match/game?
For exercise up to 90 minutes the priority should be hydration with water. For endurance exercise such as running, water is sufficient but if you are exercising at high intensity and especially in the heat you may wish to drink a sports drink. Sports drinks will contain carbohydrates and electrolytes which help to maintain water balance in and out of the cells. A number of recent studies have shown that rinsing the mouth with a carbohydrate solution without actually consuming the drink has a positive effect on exercise performance. It may be that the carbohydrate drink stimulates rewards centers in the brain!2 If you decide to make your own sports drink make sure it does not contain fructose as the main sugar as it will not be absorbed very well and main create gut problems. A good idea is to use coconut water with a pinch of salt!
There will be significant glycogen depletion when exercising for greater than 90minutes. Sports drinks or gels with water will help to maintain carbohydrate. Glycogen depletion can cause muscle wasting as protein is then used as a fuel source.
What should I eat and drink after exercise/training/match/game?
Topping up low or empty glycogen stores after prolonged high intensity exercise is essential to guarantee stores for the next session. This can be achieved by consuming a high carbohydrate snack within 2 hours or within 30 minutes if you plan to exercise again within 8 hours. Liquid carbohydrate sources will be absorbed more quickly but this is only a priority if you are training again soon i.e. the next morning. Drinking juice or eating fruit is also sufficient to replace nearly all electrolytes.
In a 1 hour workout you can use up to 30g of protein (again this depends on the type pf exercise, intensity and your own body composition). If you are having a meal with some animal protein or good non-animal protein sources as mentioned earlier then that should meet your protein and BCAA needs. However, if you are not having a meal and are on the go then it is a good idea to have some nuts and yoghurt with you. Homemade or shop bought bought bliss balls can be great, and a protein shake or a protein bar can also be useful.
Conclusion
In the long term your nutrition goals should focus on adequate:
- energy intake to meet the energy demands of training
- replenishment of muscle and liver glycogen with dietary carbohydrates
- protein intake for growth and repair of tissue, particularly skeletal muscle
- hydration
- overall diet to maintain good health
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Reference:
- NHMRC Nutrient reference values for Australia & New Zealand. Including recommended dietary intakes. (2005). National Health and Medical Research Council: Australia, & Ministry of Health:NZ.
- Dunford, M. & Doyle, J.A. (2015) Nutrition for sport and exercise. (3rd edition) Stamford, CT: Cengage.
- Cordain L, & Friel J. (2012). The Paleo Diet for Athletes: The Ancient Nutritional Formula for Peak Athletic Performance. 2nd Ed, Rodale Inc, New York.
