Questions parents ask me Posted on Thursday, September 11, 2003 - 00:00 Prepared by Shelly Meltzer RD (SA) Consultant dietitian to SARugby 1. How much protein should young rugby players eat to build muscle ? Children and adolescents do require more protein than adults because of the extra protein required for growth. Protein is also required for gains in lean body mass and to compensate for protein used as a fuel source in exercise and for muscle regeneration. But, there is a limit to the amount of protein that the muscle can use - too much protein will only be wasted. It is also important to have sufficient carbohydrate together with the protein as carbohydrate provides the necessary energy to fuel the work that the muscle must do to stimulate it to grow. It is therefore generally recommended that young rugby players consume 2g protein/kg body weight (i.e. for a 60kg player, 120g protein per day). Examples of low fat protein-rich foods are listed in the table below. Serving sizes providing approximately 10g of protein are given : 40-50g lean meat, chicken (no skin) or fish or low fat yellow cheese 2 eggs 300 ml low fat milk or yoghurt ½ - ¾ cup dried beans, lentils or split peas Some carbohydrate-rich foods also provide protein - for example 1 slice bread contains 2 g protein. Protein requirements are thus easily met if a player is eating a mixed diet of adequate energy. If however appetite is limited, encourage 3 meals with several high energy high protein snacks in between. Examples include fruit smoothies, milkshakes, fruit yoghurts, and liquid meal supplements (eg Ensure, Nestlé Buildup). Skim milk powder is a good economical source of both protein and carbohydrate and can be added to fortify milk drinks, cereals or soups.   2. Will creatine help my son’s performance ? In some situations and only in some individuals, creatine may enhance performance. Creatine however may have side effects and although a lot of these are anecdotal, no long-term studies have been done on adolescents. A concern with children taking creatine is that in a developing skeletal system the increased force of the muscle (as a result of creatine supplementation) may lead to a greater risk of injury. Also, because water is transported into the muscle cells with creatine, large doses may be disadvantageous in the heat, especially in children who already are at risk for hypo-hydration. It is therefore recommended that creatine should not be given to children under age of 18. Rather, they should stick to true natural food sources of creatine - meat /fish/chicken/lean biltong   3. What about other supplements ? Before even thinking about supplements, attention should be paid to your son’s basic diet as this will have the greatest effect on his training and performance. Remember too that performance improvement is reliant on many other factors such as growth, physiological and sexual maturation, skill acquisition, and years of training. There is therefore no quick fix to performance problems via supplements. Supplements or ergogenic aids (the list is endless and includes HMB, DHEA, ZMA) that are cleverly marketed to increase muscle mass, or to provide a performance boost and/or to increase strength are definitely not recommended for young athletes. There is little scientific evidence to support the efficacy of most of these products. Moreover, the efficacy and safety of these products has certainly not been investigated in children. Some of these costly products may also contain ingredients that could be banned and at the end of the day the onus is on your son. Only in a situation where there is certainty that your son may be lacking particular nutrients (e.g. as a result of lactose-intolerance or an aversion to milk his diet lacks calcium) it may necessary to prescribe a vitamin/mineral supplement. But this should be monitored by a health professional. In may also be practical in some situations to use supplements such as skim milk powder, liquid meal replacements, and carbohydrate powders (see point 1, 6, 10).   4. Are sports drinks necessary for young rugby players? Drinking is important to replace fluid losses and fluids can also provide energy in the form of carbohydrate. Sports drinks provide both carbohydrate and fluid but so does fruit juice (preferably diluted by 50%), diluted cordial (e.g. Oros), or even a carbohydrate powder (e.g. Fast Fuel, Runners Fuel, Refuel powder) when added to water. Although sports drinks may contain some other nutrients (eg some electrolytes like sodium and potassium), snacks and food generally provide a more significant amount of these electrolytes. Some sports drinks may have added Vitamin C, which is of course present in most fruit juices. So when it comes to choosing between any of the above drinks, choose what suits your pocket and a flavour that your child enjoys since if he likes the taste, he is likely to drink more.   5.My son just refuses to eat fruit and vegetables. Can he just replace this with vitamin and mineral supplement? The best strategy to obtain adequate nutrients in a form that is well absorbed by the body is to eat a variety of food. Of course fruits and vegetables are especially rich in many vitamins, minerals and other phyto-nutrients. But, 91% of children aged 6-11 years do not consume the recommended minimum of 5 servings of fruits and vegetables per day. Most children average 2 ½ fruit servings a day making it difficult to achieve adequate intakes of many vitamins. If your child has a particular aversion to fruits or vegetables first try some of the following tips before buying a supplement: Add vegetables to stews, soups (even pureed), casseroles, stir fries, and to meat or chicken kebabs Encourage fruit-based desserts (apple sauce, banana-filled pancake, baked apple, fruit kebabs) Make fruit salad (often a child is too lazy to cut up the fruit) Dried fruit is a concentrated source of many nutrients Fruit juice and veggie juices or smoothies should take preference over colddrinks. 125 ml fruit juice counts as a fruit serving.   6. My son finds it challenging to eat all the carbohydrate that is recommended Carbohydrates can be bulky and filling especially if they are rich in fibre. Applying the following tips will help boost carbohydrate intake: From the start to the end of the day, ensure all meals are based on carbohydrate-rich foods (grains, cereals, vegetables like potato, sweet potato, pumpkin) It is best to split total carbohydrate needs into several meals and snacks throughout the day. If your child skips breakfast either because of lack of appetite or time or interest, suggest a smoothie made with fruit juice; or fruit and yoghurt; or crumpets/brumpets with jam/honey topped with grated cheese and served with a glass of juice; or cereal with sliced banana and milk served with a glass of fruit juice. If your child ‘just can’t get going in the morning’ pack a portable breakfast of a muffin, a wedge of cheese and a juice to be eaten on the way to school. Snacks between meals are important opportunities to sneak more carbohydrate (and some lean protein) in. Pack any of the following nutritious snacks into tog bags: fruits, fruit sticks (as a treat add in some biltong sticks), crackers with cheese wedges, pretzels or sweetened breakfast cereals and yoghurts, low fat cereal bars, sports bars, carbohydrate-containing beverages, nuts and raisins, bread and jam and peanut butter. Foods and drinks can be fortified with glucose polymer powders (e.g Refuel, Runners Fuel). Liquid meal supplements like Complan, Buildup or Ensure can also be used. Sports drinks do provide an opportunity to meet daily carbohydrate requirements, but players should not rely on these drinks as a major source of carbohydrate as this will then negatively impact on their vitamin, mineral and fibre requirements.   7. Is all this carbohydrate detrimental in terms of dental health ? Dental caries or tooth decay is the result of repeated acid attacks by bacteria on dental plaque. Fermentable carbohydrates present in foods and beverages provide the necessary substrate for enhancing acid production. Eating or drinking sugary foods and beverages between meals, without regular cleaning of teeth will promote dental caries. Factors associated with dental caries are: The amount of fermentable carbohydrate consumed The physical form of the carbohydrate and the stickiness of the food The concentration of sugars in the foods consumed The length of time the teeth are exposed to acid The frequency of meals and snacks The proximity of eating before bedtime Specific foods like citrus fruits and juices, carbonated and un-carbonated sugary drinks, acidic herbal teas, vinegar and vinegar products, sweets, acidic medications and supplement (eg vitamin C tablets and syrups) To prevent dental caries, encourage your child to: Brush and floss his teeth regularly (this is very important if your child wears braces) Rinse his mouth frequently with water Eat casein-containing food like milk/cheese Chew sugar-free gum Drink through a straw or squeeze bottles directly into his mouth as this minimizes contact time with teeth Have drinks chilled as the erosive potential of acidic drinks is temperature dependent Always be adequately hydrated as this will promote saliva which is an important buffer that prevents erosion.   8. Why is fluid so important and how much fluid should my child be drinking ? For several reasons young rugby players are especially susceptible to acute dehydration and this may affect cardiovascular function, temperature regulation and exercise performance: Children have less developed and, therefore less efficient thermo-regulatory mechanisms than adults. They therefore have a higher risk of hypothermia in cold environments and dehydration and hyperthermia in hot environments. On average, young children only produce more than 400 - 500ml sweat/m2 per hour whereas adults under the same conditions can produce more than 700 - 800 ml of sweat/m2 per hour. Young athletes often begin training after school already hypohydrated. As a broad guideline your child should “drink periodically until he is not thirsty anymore, and then another few gulps”. For a child older than 10 years another few gulps is 200-250ml beyond thirst (Bar-Or, 1995). However, the best would be for each young rugby player to determine his own requirements for fluid in different temperature conditions. This can be done by weighing himself on a bathroom/portable scale before and after training in minimal clothing and after towel drying, measuring the volume of fluid consumed during training or lost as urine, and then determining the change in his body mass. Every 500g sweat loss is roughly equal to 500ml fluid. Therefore, Sweat loss (mL) = Change in body mass (g) + Fluid intake (mL) - Urine losses (g) To remain in fluid balance he should consume fluid equal to his sweat loss: Example: Wayne’s weight before practice = 70 kgs Wayne’s weight after practice = 69.8 kgs Practice session = 2 hours During the practice session he drank = 500 ml fluid He did not have any urine losses Wayne’s sweat loss (ml) = 200 (g) + 500 (ml) = 700 ml This is therefore the total amount of fluid he should have consumed in the 2 hour period. Of course he may have difficulty drinking this amount all at once so he should be encouraged to have smaller amounts and to drink at regular intervals. It is advisable to have about 200-300 ml of fluid about 45 minutes before a practice session and then to top up his drink bottle so that during the practice he can have smaller, more tolerable amounts at regular intervals. He should be reminded that it is important to practice drinking strategies when training as he will then be accustomed to tolerating greater volumes and will soon learn to drink at a rate that matches sweat losses as closely as possible. After training he will still continue to lose fluid and so should continue drinking until he is urinating frequently.   9. My child is constantly tired. Can this be related to his diet ? Of course there are other factors that may be a cause of your child’s tiredness like over-training and lack of adequate sleep, but nutrition should not be overlooked. Attention should be paid to your child’s overall energy and carbohydrate intake, his protein intake, as well as certain vitamins and minerals. Lack of dietary iron for example, may be a cause of fatigue. (Rich food sources of iron include meat, chicken, biltong, liver, spinach and some dried fruits), It is also important to consider post-training nutrition. After exercising, there is a ‘window-period’ of 1-2 hours in which time the muscles have an accelerated ability to replace carbohydrate stores. So pack with something for your child to have after training, particularly if he spends a considerable amount of time travelling home from training. A sandwich with a filling of cheese, fruit-flavoured yoghurt, a carbohydrate drink or fruit juice with a few crackers or a raisin bun or a cereal/sports bar. Provided the snack provides sufficient carbohydrate (about 50g - see 50g carbohydrate list for portion size) you can include some protein. Protein may be especially important if there has been any muscle damage.   10. When my son goes away on rugby tour, I know that he doesn’t eat properly If your child does not enjoy trying new foods or you are concerned about the food on tour it is always a good idea to pack a supply of familiar foods to take with. Fruit, dried fruit, crackers, pretzels, muesli bars, breakfast bars, dry cereal (in serve size packets), skim milk powder, a tin of Buildup Powder or Ensure, fruit juices, instant oats or quick cooking noodles (if a kettle is available), carbohydrate powders (eg Refuel or Runners Fuel) are all suitable options.