Sports Nutrition

Guide to Fueling the Teenage Athlete

By August 9, 2019 No Comments

By now, football two a-days are in full swing and high school athletes everywhere are gearing up for fall competition season.  I remember my boyfriend in high school dreading these practices and struggling to feel fully recovered from day to day.  If I knew then what I know now, I could have really helped him!

If you are a parent of a high school athlete and you’re struggling with how to help them fuel and hydrate appropriately during these early practice days, and even throughout the season, use my tips below!


Many teenage athletes, and their parents ask me, how many calories do they need?  This might seem like a simple question, but a lot goes into calculating total calorie needs.  First of all, males and females enter puberty at different ages, which means that the need for increased energy to support their growth and changes in body composition and bone mass comes at different ages.  Also, after puberty, athletes come in all shapes and sizes.  We also need to consider physical training, sport-specific practice, and competitions; all which results in highly variable energy needs. 

Although we do not have evidence to prove it, there is reason to assume that young athletes expend more calories than adults do during exercise, because we do know that children have higher resting energy expenditure than adults do.  Simply, stated, per kilogram of body mass, children burn more calories at rest than adults do.  The difference in their stride and muscle contractions likely play a role in increased energy demands during exercise.  Young athletes are less efficient in their movements, which results in a high calorie demand; however, as they become better trained in their sport, their energy demands likely decrease.  Below is a chart that gives estimated calorie needs for males and females based on age and activity level. 

Adapted from “Fueling Young Athlete” by Heather Mangieri


Our bodies use the carbohydrates we eat to provide energy.  Carbohydrate is the preferred source of fuel for working muscles and it supplies a steady source of energy to feed the brain and the nervous system.  Foods rich in carbohydrates, whether simple or complex, are broken down in the body into glucose, which can be used immediately or stored in the liver and muscles until it is needed. 

Both simple and complex carbohydrates can add value to a teenage athlete’s performance, but the amount and timing should be considered. Complex carbohydrates are digested slowly and should make up the majority of a teenage athlete’s diet, as they provide a steady source of energy throughout the day.  Simple carbohydrates digest quickly, thereby providing a great source of fuel when energy is needed quickly, such as immediately before an event, during an event, or between events.  During football practice simple carbohydrates, from something like a sports drink or a chewy granola bar, will help to provide immediate energy.

The muscles are limited in the amount of carbohydrates they can store.  When muscle glycogen stores are used up, which happens during very intense and/or long durations of exercise, athletes have less energy, causing them to lose focus and decreasing the intensity and quality of their performance.  Eating adequate carbohydrates also spares the breakdown of protein for energy.  When enough calories are consumed, and the right amount is suppled as carbohydrate, protein can be used for what it is intended for (growth and repair), rather than be broken down and used for energy.

Carbohydrate needs increase, based on the developmental age of the athlete, as well as the type, intensity, and duration of training.  As growing athletes enter puberty and experience growth spurts, their carbohydrate intake needs to increase.  The higher the calorie needs are, the higher the carbohydrate intake must be.  Below are some photos that show how much of the athlete’s plate should be made up of carbohydrates for light, moderate, and heavy training.


The only way to build lean muscle tissue is to put muscles to work and to eat an adequate amount of protein to support repair and growth.  As with carbohydrates, teenage athletes have a greater protein requirement than nonathletic teens.  Protein guidelines for teenage athletes are not easy to access; however, general recommendations range from 1.0 to 1.8 grams per kilogram of body weight.  This may change for weight-based sports, like wrestling, where weight may need to be cut and protein needs increase.  For endurance athletes the range is 1.2 to 1.7 grams per kilogram of body weight.  Looking at a plate, this should be about a quarter of their plate, or about the size of their palm per meal.

Protein should be evenly spread throughout the day; however, one time specifically during the day is extremely important for athletes to consume enough.  Post workout is when muscles are broken down and need to be repaired.  Research shows that 0.25 grams per kilogram of body weight is the best amount of protein post workout for athletes.  Most athletes should strive to get between 15-30 grams of high-quality protein 30-45 minutes post workout.  And this includes during two a-days!  

Dietary Fat

Carbohydrate is known to provide the best fuel for working muscles; however, fat is also a valuable source during activity, especially in teenage athletes.  Children and teenagers have higher fat oxidation rates than adults, suggesting that fat is a very valuable fuel during prolonged activity, like distance running or two a-day practices.

When the intensity of a sport decreases and the body has more oxygen available, such as during long-distance running or cycling, more fat is used as energy.  These endurance type sports require a combination of glycogen and fat for energy.  For teenage athletes, fat amount increases as training increases – anywhere from 1 teaspoon per meal to 2 Tablespoons per meal is appropriate. Also, fat should be coming from helpful sources, like fatty fish, eggs, nuts, seeds, avocados, and olive oil.


We can’t talk about sports nutrition and not talk about hydration – this is the easiest, cheapest, and most effective way to promote optimal performance, especially in teenage athletes!

Water is actually the most vital nutrient and is used in 99% of bodily processes.  In adults, just a 2% loss in body water has been shown to cause adverse performance effects; in adolescent athletes those negative effects seem to occur sooner; with just a 1% loss of body weight in fluids.  The effects associated with dehydration in young athletes lead to decreased endurance and performance by negatively effecting the cardiovascular system, thermoregulation, and perceived exertion. 

Athletes can determine their individual sweat rates by recording their weight pre and post practice.  For every pound lost during exercise, they should consume at least 3 cups of water to replace it. 

During activity, some general guidelines include drinking 3-8 ounces of water or sports drink in hot environments or with heavy sweating, every 20 minutes.  Sports drinks are warranted in hot, humid environments or when exercise is over an hour long.

Hopefully, this guide provides you with some information on the teenage athlete’s fueling needs and can help set your athlete up for success during these early practice days and going into the season.  If you need some great meal ideas, head on over to my resources page and download the Team Meals document.

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