Content provided by: Tiffani Ghere, Clinical Pediatric Dietitian
NUTRITIONAL DEVELOPMENT FOR ATHLETES
Energy balance is needed for athletes. All athletes compete to win, and want to perform at the top of their game — but young athletes with poor eating habits may find themselves with insufficient fuel for workouts. The key to success is finding the right amount of food to fuel performance and growth without over consuming calories that increase body fat. Much of the research on athletes, historically, is focused on adults, but scientific evidence does point to some key issues regarding children and sports nutrition. Growing children engaged in strenuous exercise need special consideration. A lack of nutrients can lead to fatigue and/or illness, a decrease in bone growth or density, and may actually prevent youths from reaching their growth potential for height and muscle mass.
It's important to note that, while adult athletes might practice these things, there isn’t enough evidence to support carbohydrate loading or excessive protein intake in children. Creatine, as a supplement, is NOT recommended. Iron-rich foods should be encouraged, and, in female athletes, nutrients for bone maintenance are imperative*. Finally, adequate hydration is absolutely essential for peak performance.
*Current Opinion in Clinical Nutrition & Metabolic Care
May, 2009 v 12; issue 3 pp 304-309
Following is a broad compilation of nutritional requirements for young athletes.
MACRONUTRIENTS | 9-18 year olds
Adequate intakes promote glycogen stores and prevent fatigue. Glucose is the first, most desirable form of fuel by the brain and body. Because of this, 55% of calories for athletes should be from carbohydrate sources. If it is not available, the body must go to another source like protein via gluconeogenesis, to break down muscle to make glucose.
3-5 gms/kg body wt for light training
5-8 gm/kg for moderate to heavy training
8-9 gm/kg for pre-event training
1.7 gms/kg for post-event recovery (within 2-3 hours)
Sources: whole grains, fruits and vegetables
Used for building, repairing and maintaining muscle. Protein balance cannot be maintained without energy balance (absence of enough calories)
ADA recommendations for young athletes:
Beginning of training program: 1-1.5 gms/kg/day
Too much protein can lead to dehydration, weight gain or increased calcium loss.
Endurance sports: 1.2-1.4 gms/kg/day
MICRONUTRIENTS | 9-18 year olds
CALCIUM | Adequate Intake = 1300 mg/day
Needed to support bone growth, aid nerve impulses and muscle contraction. Because a child’s bones are not as resilient as adults, overuse and overtraining injuries are more common than in adults.
Sources: dairy, yogurt, cheese, orange juice fortified with calcium, kale, broccoli.
IRON | Adequate Intake =15 mg/day
Used to carry oxygen in the body and also used for energy metabolism of carbohydrates, proteins and fats. Symptoms of iron deficiency include fatigue, decreased work capacity, impaired immune function and impaired cognitive reasoning. However, iron toxicity is a major concern when supplementation is given. It is a very common cause of poisoning death in young children. Optimizing nutrition is the best first choice for anemia. Supplements should only be taken under a physician’s advice.
Sources: red meat, whole grains, poultry and cooking acidic foods in a cast iron skillet.
Utilized in metabolic processes and essential for blood health and neurological function.
Sources: enriched whole grains and meats.
Deficiency is rare in the US, but athletes are at risk if consumption is poor. It plays a role in over 300 enzymatic reactions and wound healing. It affects basal metabolic rate, protein utilization and thyroid function. Dietary protein enhances absorption.
Sources: turkey - dark meat, pumpkin and squash seeds, yogurt, brown rice, oatmeal, beans/peas.
ESSENTIAL FATTY ACIDS | Polyunsaturated fatty acids
[PUFA] Omega 3’s EPA, ALA, DHA. These fats are not made in the body and must be consumed in the diet. Play a role in brain function, immune and cardiovascular health and reduce inflammation. Omega 3’s may reduce triglyceride levels.
Sources: salmon, halibut, mackerel, flax, canola oil, walnuts.*
Sports Nutrition for Young Athletes: Vital to Victory
Pamela M. Nisevich, MS, RD, LD
Today’s Dietitian v10; No 3 pp44
Most people think of dairy sources when asked where we get calcium. But even for the non-dairy kid, there are still many good options for calcium in food. Listed below are some sources for calcium, both dairy and non-dairy:
Milk 8 oz 300 mg
Orange juice, fortified 0 oz 300 mg
Cheddar cheese 1.5 oz 300 mg
Tofu, fortified 4 oz 260 mg
Yogurt 6 oz 225 mg
Almonds 1 oz 80 mg
Bok choy 1/2 cup 80 mg
Cottage cheese 4 oz 70 mg
Red beans 1/2 cup 40 mg
Broccoli 1/2 cup 35 mg
There are many good options for iron in food. Listed below are some sources for
iron for your athlete:
Potato, with skin
Goji berries - have been measured to have more than 15 times more iron than spinach.
Strongly associated with fatigue during exercise and increased in environments of high heat and humidity. Children heat more readily due to a higher surface area to body mass ratio. Signs of dehydration: decreased urine output, dark urine, muscle cramps, headaches, nausea and increased heart rate.
Drink water for activities lasting less than 60 minutes.
Drink selected sports drinks with 6-8% carbohydrate for activities grater than 60 minutes, to replace electrolytes and energy lost.
BALANCE YOUR BEVERAGE | Activity: Bike Riding
ENERGY IN ENERGY OUT
8 oz Vitamin water | 50 calories 10 minutes
Soda | 290 calories 55 minutes
Sports Drink | 140 calories 30 minutes
Grape Juice | 95 calories 20 minutes
WATER AND PROPER HYDRATION
With the added sports in the middle and high school years, hydration is more important than ever. Drink water instead of high-sugar sodas, juices, or “energy” drinks. Coconut water is an excellent option.
* Healthy Schools Partnership
For more information visit kidshealth.org
NOTE: These are general guidelines. Please consult your pediatrician for specific needs.