Running will always be a good sport for young athletes. If I’ve learned one thing teaching PE for the last 9 months, with a bit of practice, even those who say they don’t love running can do it. If you have a kid that loves to run, you need to know about sports nutrition for young endurance runners. They need a lot of calories, especially when runs get longer.
Nutrition for young runners is hard on parents and kids alike. Take the energy demands of the sport and pair that with energy demands of growth and it may seem like the refrigerator door never closes.
Sports Nutrition for Young Endurance Runners
Energy Needs
There is a lot of emphasis put on carbohydrates for endurance exercise, and for good reason. The choice of fuel for your body depends on 3 things: diet, intensity of exercise, and training. Let’s break it down.
If the diet is varied, your body will pull from carbohydrates and fat during a run. If the body is short on carbs, it will metabolize fat. This is not a good thing for young runners who don’t need to lose weight.
Intensity of exercise will largely determine the fuel source. Low intensity exercise relies on fat more than carbohydrates for energy, whereas high intensity exercise will rely more on carbohydrates.
Carbohydrates are stored in the muscles and liver and it’s called glycogen. The body can easily pull from these, so keeping a good supply of carbohydrates in the diet is perfect for a young runner. Your body pulls muscle glycogen first for runs lasting longer than an hour. After the first hour, then blood glucose becomes more important. This is also why you see endurance runners start to refuel after an hour of running.
Trained athletes will use fat more efficiently than non-trained. So, as your runner progresses in their training, the fuel source will change. One caveat to this is, if a high carbohydrate meal or drink is consumed within 60 minutes of the run – the body will naturally use more carbohydrates for fuel due to the rise in insulin.
So, for a review, long periods of endurance exercise (longer than 30 minutes) at low intensity will use a higher percentage of fat for fuel, while also using carbohydrates. Higher intensity endurance running will use more carbohydrates for fuel and less from fat.
Calorie Needs for Young Endurance Runners
So, what does all this mean in terms of calories? You want to make sure you child is getting enough calories, but this shouldn’t stress you out. Your child should eat when they are hungry and stop when they’re full.
If you need a general recommendation of calories, here is a guideline:
Active males 14-18: 2800-3200 calories/day
Active females 14-18: 2200-2400 calories/day
Carbohydrates
Endurance runners hear about good carbohydrate sources all the time. Now that you know why the body needs carbs, what’s the best way to eat them?
Carbohydrates aren’t simply bread and pasta. They are fruits, vegetables, all grains, beans, nuts, and dairy.
Most carbohydrates also have other macronutrients as well. Dairy and nuts are two examples of this. They have all 3 macronutrients — carbohydrates, fats, and proteins.
Carbohydrates need to be eaten all day, not just before a run. When they are steadily eaten, it gives the body a chance to store them to be used for energy. The carbohydrate recommendations for athletes should be high enough to cover energy needs for performance and growth.
- Moderate intensity exercise (60 minutes/day): 5-7 g carbs/kg body weight
- Mod to high intensity endurance exercise (1-3 hours/day): 6-10 g carbs/kg body weight
They also need to be consumed after a run. Early refueling is typically only necessary for exercise that is less than 8 hours apart, but can also be beneficial for kids who are running everyday. This can be done by eating 1-1.2 grams carbs/kg body weight within 60 minutes post exercise and then having a nutritious meal with carbohydrates, fats, and protein within 4 hours.
If long runs are not back to back, regular refueling is all that is needed and for most kids, this is appropriate. Since most kids are starving after a run, this is usually not an issue.
Protein
In addition to carbohydrates after a run, young runners should also have protein. Protein may help the body optimize glycogen storage. Typically the ratio of protein to carbs post-exercise is 1:3.
So, what does this look like? For a young runner who is 110 pounds (50 kg), she should eat around 50 grams of carbohydrate (200 calories) and 17 grams of protein (67 calories) with a little fat after a workout.
- 1 large apple with 1/4 cup peanut butter
- 1 large pita with 1/4 cup hummus
- Turkey sandwich
Daily protein needs are anywhere between 1.3-1.8 g/kg body weight, so again, for our 110 pound athlete, her daily needs are 65-90 grams of protein per day.
A good mix of different protein sources will ensure your runner has all of the amino acids they need throughout the day to help repair and build muscle.
Fat
Since you already know that fat is metabolized during long, slow runs, it only makes sense that your runner is getting fat from their diet. The recommendation for fat is 20-35% of calories. Make sure those are healthy fats. Here are some good options:
- Olive oil
- Nuts & nut butters
- Avocado
- Fish
- Flaxseeds
A few notes on fat. Fat slows down digestion, so it’s not a good idea to have a lot of fat prior to running, it can cause some gastrointestinal issues for your runner. Keep the fat 3-4 hours prior to a run, and after their run for best digestion.
Limit the amount of unhealthy fats in the diet. Shelf stable and ultra-processed foods can have trans fat and a bunch of added sugar in them, so limit those.
Other Nutrients to Consider for Young Endurance Runners
If your child eats a variety of foods everyday, then they are most likely getting all of the nutrients they need for growth and for running. However, here are some exceptions to this:
- Special diets: If your child is a vegan or a vegetarian, they may not be getting enough iron, vitamin D, protein, calcium, or vitamin B12. Stay aware of these nutrients.
- Picky eating: If your child eats the same foods everyday or has very picky eating patterns, they may become deficient on various nutrients depending on what is absent from their diet. Encourage them to try new foods. Athletes usually will do what it takes for performance.
- Female runners: The strike of the foot against the ground may cause the destruction of red blood cells and since most of the iron in our body is found in red blood cells, this could be a problem, especially for girls. Pair this with a monthly menstrual cycle and your young female athlete runs the risk of low iron. Fatigue is typically the first symptom of low iron. Never supplement without getting a blood test first and recommendation on dosage from your doctor.
Bottom Line
Feeding young athletes can be stressful, but it doesn’t have to be hard. Keep the house stocked with healthy choices and lead by example. Encourage water for hydration and steer clear of sugary drinks and soda.
If you feel stuck, seek help from a sports dietitian or health care provider.
Resources for this article
Dietary Guidelines for Americans: https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/appendix-2/
Karpinski C., & Rosenbloom C. (2017). Sports Nutrition: A Handbook for Professionals. 6th edition. Chicago, IL. Academy of Nutrition and Dietetics.
Powers, S.K. & Howley, E.T. (2018). Exercise physiology: Theory and application to fitness and performance (10th ed.). McGraw-Hill.
