There are many questions about optimal nutrition for our super athletes here at NorCal Rush. Nutrition should support their normal growth and development, but also the increased needs as a result of training. It is also important to create good and healthy nutrition habits that will benefit any athlete later in life. Nutrition is an important part of the athlete’s life, but unfortunately, it is not always treated as such.

Young soccer players are not just smaller versions of adult soccer players! Our players must have different nutritional needs because they are in a phase of growth, and their physiology and metabolism are different from adults. Here we will discuss the background, as well as some of the practical implications of nutrition for young athletes and their parents.

GROWING AND DEVELOPING

The growth in height of pre-pubertal children between the ages of 2 and 10 years is linear and occurs at a rate of 2.4 inches per year. The median heights and weights for boys and girls are similar, averaging 2ft 10 and 26.5 lbs at the age of 2 years to 4ft6 and 70lbs by the age of 10 years. The age for the onset of puberty varies among individuals. Children and adolescents need adequate energy intake to ensure proper growth, development, and maturation.

Dietary Reference Values (DRVs) have been established for various ages, but for the athletic or highly physically active child or adolescent, these recommendations will need to be adjusted for the level of physical activity. In adolescents, in particular, the onset of the growth spurt, which is a major reason for increased energy requirements, is unpredictable and it is very difficult to estimate energy requirements. It is well known, though, that prolonged inadequate energy intake will result in short stature, delayed puberty, poor bone health, increased risk of injuries, and menstrual irregularities or absence in girls.

Behavior

It is important to educate children to eat a “healthy and balanced” diet and to encourage good eating habits. For the aspiring Rush Soccer Player this should also include specific sports nutrition guidance with performance goals in addition to health goals. This can reinforce lifelong eating habits that contribute to the overall well being of children and may enhance sport performance. On the other hand, any bad habits developed in childhood and adolescence may be difficult to eradicate later in an athlete’s sporting career and should therefore be avoided. There is an important role for parents, coach and support staff to encourage appropriate eating behaviors, but also to avoid bad habits, such as too much attention to body shape and body weight

For parents:

• Practice responsive parenting by discriminating hunger from other distress cues and avoiding always using food to comfort your child

• Provide positive, repeated exposure to novel foods (especially typically rejected foods, such as vegetables) to promote acceptance of and preference for those foods

• Offer developmentally appropriate and healthy foods to your child during the transition to solids

• Serve portion sizes that are developmentally appropriate for your child’s age and nutrient needs

• Choose when and what your child should eat, but let your child decide how much to eat

• Trust a child of normal weight status to self-regulate his own intake

• Make a wide variety of nutrient-dense rather than energy-dense, nutrient poor foods available and accessible to your child

• Use your own behaviors and attitudes to model healthy dietary patterns

• Create a positive feeding environment by initiating regular family meals

DIFFERENT METABOLISM IN CHILDREN

There appear to be some differences in fuel use between adults and children. Young soccer players are a bit more like the muscles of endurance athletes (aerobic) and not yet developed for very high intensity (anaerobic) exercise. Our younger player's capacity to produce lactate is lower than adults and this means it is more difficult to sustain high-intensity exercise. Therefore they rely very much on fat as a fuel than adults. These differences, however, seem to diminish throughout adolescence, especially in boys, suggesting that the hormones associated with puberty play a role in regulating energy metabolism in children.

In order to support their growth and development, children and adolescents have protein requirements that are relatively high compared to adults. The Recommended Daily Allowances (RDAs) for protein in the United States are between 1.05 and 0.80 g/kg depending on age with the highest recommendations for 1-3-year-olds and lowest for 18-year-olds.

However, as for adults, the protein requirements for young elite athletes are likely to be even higher. These requirements may be as high as 1.4 g/kg/day when young athletes play 10-12 h/wk. This would be around 75 g/d in this group, well above the RDA (52 g/d) for children of this age in the general population. However, when athletes are following a complete, well-balanced diet with adequate protein sources, this requirement is easily met with higher daily energy intakes of highly active individuals. On the whole, protein requirements seem to be of no particular concern for most young athletes. Nevertheless, it is important to be aware that there may be some individuals, who, perhaps due to intentional energy restriction for weight loss or a vegetarian diet, have protein intakes well below the recommended amounts.

It is well known that carbohydrate ingestion in adults both before and during exercise can delay fatigue and improve endurance performance. Unlike protein, which has a quite general recommendation, recommendations for carbohydrate intake rate highly dependent on the intensity, duration, and type of exercise that is performed by young athletes.

Although it is important to eat enough carbohydrate to fuel the activity, carbohydrate loading, such as is common practice in endurance sports to increase muscle glycogen levels, is not needed and not advised for children. Since generally their activities are shorter or require less glycogen and their ability to break down carbohydrate is limited, it must be questioned whether such a strategy would be beneficial at all. A relatively high carbohydrate diet is advised but there is no need to follow a dedicated glycogen-loading regimen.

Children can benefit from carbohydrate intake during exercise, as adults do. But this is only useful when the exercise is high enough intensity and long enough duration. Many children will be physically active or engage in regular training but may not reach the level of physical activity that would warrant the use of carbohydrate beverages. However, those young athletes training hard and long enough will probably benefit.

One of the main ways that humans lose heat is through the evaporation of sweat from the surface of the skin. As children have a higher ratio of body surface area to body mass (at the age of 8-years-old it is approximately 50% higher than that of an adult), it has been suggested that exercising children should be able to dissipate heat quicker than adults. This should give children an advantage in terms of their thermal homeostasis over that of exercising adults, at least up to the point at which ambient temperature exceeds skin temperature, after which this advantage is supposedly reversed. In practice, however, this has not been found to be the case and adults and active children seem to experience similar body core temperatures, even when exercising at high ambient temperatures. Whether the same finding would occur in young athletes, as compared to these active, but not competitive children, is yet to be determined.

High sweat rates in hot conditions can result in large fluid and electrolyte losses. In adults, the dehydration caused by this fluid loss has been shown to impair both motor control and physical performance, so adults are advised to balance any fluids lost from sweating, with fluid intake or to at least to limit losses to no more than 2% of body mass. However, there are large differences in sweat rates between children and adults. In fact, 9-year-old boys exposed to hot and humid conditions (13.00 °F and 97% relative humidity) had an average sweat rate that was only half of that of men. 

Thus the recommendations regarding fluid replacement are likely to be similar too. The policy statement by the American Academy of Pediatrics, regarding the fluid replacement guidelines for children during exercise in the heat state that a child who weighs 88 lbs should drink 5 oz. of cold water every 20 min and an adolescent who weighs 132 lbs should drink 8 oz. every 20 min, even if the child does not feel thirsty. Such guidelines are very general and do not take into account important factors such as environmental conditions, exercise intensity, acclimatization and individual differences, but it gives perhaps a rough indication. At an elite level, it seems sensible to develop an individualized strategy that aims to reduce fluid losses in excess of 2-3% body mass. In general, involuntary hypohydration can reach up to 1-2% of body mass loss in boys and this in the vast majority of cases dehydration is not a major issue.

Check Your Foundation.

This may be easier said than done and not everyone may actually agree with what healthy means. But one thing everyone will agree on is that heavily packaged foods are generally not as healthy as unpackaged “fresh” foods. Foods that are rich in fiber are also generally healthier than foods that are very low in fiber.

Read labels.

Often products marketed for kids contain a lot of unnecessary calories. Read labels and watch out for high sugar and high saturated fat content and choose those with higher fiber content.



Keep an eye on size.

Children are not the size of adults, so their meals should be smaller. Also, make sure snacks do not meal replacements.

Plan ahead.

Sometimes bad nutrition choices are inevitable when traveling and you don’t have access to the foods you would like. The temptation exists to stock up at gas stations whilst you could be eating homemade healthy food, so plan ahead.

Eat around the exercise occasion.

To recover quickly, it is thought that carbohydrate intake helps to restore muscle glycogen and protein starts that repair process. Although the window of opportunity may not be as critical as sometimes claimed, the hour after training (or games) is the most effective period for glycogen synthesis and also very effective for increasing protein synthesis.

Stay hydrated.

Make sure you stay hydrated. This can be done by drinking 3-8 oz. two hours before training.

Measure weight loss.

Trainers can measure weight loss before and after training and even calculate sweat losses. This is educational and will help to identify those individuals who sweat more and may need to drink more, especially on hot days. It can also help to identify individuals who are gaining weight and thus, are drinking too much.