Consuming a sports drink is a convenient way to add carbohydrates, fluids, and electrolytes, when deemed appropriate, during exercise. Use of sports drinks outside of physical activity can lead to excessive sugar and calorie intake, which may lead to dental caries, being overweight, and obesity.11 Use of a sports drink during activity should be suggested on an individual basis based on training environment, duration, intensity, and the teen's overall health.
It is important to note sports drinks and caffeinated energy drinks are not one-and-the-same. A sports drink is a “flavored beverage containing carbohydrate, minerals, electrolytes (eg, sodium, potassium, calcium, and magnesium), and sometimes vitamins or other nutrients.”11 An energy drink is usually characterized by containing stimulants (caffeine, green tea extract, and guarana), along with carbohydrates, amino acids, vitamins, and minerals.11 Making sure adolescents know the difference and risks associated with energy drinks is crucial.
Some athletes may be considered “salty” sweaters and require extra sodium in their diet. Signs of excess salt loss include sweat that burns/stings the eyes, caked salt (salt on skin, clothes, and hats), and sweat that tastes salty.10 In this case, using a sports drink or adding a small amount of extra salt (1/4 teaspoon of table salt per 1 L of water) to fluids might be necessary. Encouraging the athlete to eat salty snacks such as pickles, crackers, pretzels, and/or adding salt to foods can also help.
Adolescent athletes will gain more performance improvement through healthy growth, maturation, regular training, and adequate nutrition than any supplement may provide. There is limited research on the short- and long-term risks of supplement use in athletes younger than 18 years. Education needs to start earlier within sports teams and schools about the efficacy and safety, or lack thereof, for performance-enhancing substances/supplements. As stated previously, making sure adolescents know the difference and risks between energy (caffeine-containing drinks) and sports drinks is needed.
There are a lot of fad diets touting the benefit of improved performance to the athletic population. Some of these trending diets do have merit for health, such as a gluten-free diet, when medically appropriate, but do not enhance athletic performance. Athletes who exclude certain foods or food groups are at risk of not meeting nutrition guidelines for general health and sport. There are pros and cons to any diet, as well as potential benefits and consequences for the athletic population.
Low-Carbohydrate High-Fat or Ketogenic Diet
The premise behind the ketogenic diet is to limit the amount of carbohydrate available for the body to use as fuel, thus increasing the ability of the body to use fat for energy during exercise.12–14 In most research, a high-fat, low-carbohydrate diet presents as less than 60% to 65% of total energy intake from fat and carbohydrate below 20 g per day or less than 20% of total energy intake. Although the use of a high-fat, ketogenic diet revealed higher rates of fat oxidation, no performance benefits have been shown in endurance or high-intensity exercise thus far.12–14 The capacity for high-intensity exercise is actually at risk of being compromised while following a ketogenic diet.13,14 Research is still exploring the area of ketogenic diets in sport, particularly with ultraendurance sports.
To truly follow a high-fat, low-carbohydrate diet, as described above, would be extremely difficult for the adolescent population. Personally, I do not advise eliminating foods or food groups if it is not medically necessary. Consuming less than 20 g of carbohydrates a day would remove foods such as milk, yogurt, fruit, grains, and starchy vegetables. Carbohydrate foods provide not only the body's preferred energy source, but also vitamins, minerals, and fiber necessary during the growth and development stage of adolescence. Eating a high-fat diet may also lead to a greater intake of saturated fats, playing a factor in increasing the risk of obesity, cardiac disease, etc., later in life.
The Paleolithic (paleo) diet is built around the approach of eating like caveman in the Stone Age nonprocessed, whole foods.15 Foods considered paleo are fresh fruits, vegetables, lean meats, poultry, eggs, fish, tofu, nuts, and seeds. Cereals, grains, legumes, and dairy are excluded from the diet. In short, the principles behind the paleo diet lead to low carbohydrate (nonstarchy vegetables and fruits), higher protein, and moderate to higher fat intake. Since dairy is eliminated, calcium intake usually is low. A study by Osterdahl et al revealed that calcium intake on the paleo diet was at 50% of the recommended dietary intake.16
While this regimen promotes intake of fruits, veggies, lean proteins, and healthy fats, it is very restrictive. The amount of fruit “allowed” in a day is restricted, and as stated before, starchy vegetables, grains, and legumes are eliminated. Such restrictions favor low carbohydrate intake, which can affect energy levels, nutrient, and total calorie intake for athletes. Many “allowed” fresh foods may also be inconvenient for an adolescent athlete to pack and keep for a period. The cost of the paleo diet is reported to be 10% more expensive than a nonrestrictive diet of similar nutritional value.17 While adhering to a paleo diet may decrease body weight and/or body fat percentage, there are less restrictive ways to get the same result.15,17
Utilization of intermittent fasting is more commonly used as a weight loss method than for increased performance. However, many athletes believe the leaner they are, the better they will perform. Intermittent fasting involves fasting for a period with little to no caloric intake.15 Normal eating then resumes after fast. The idea is that fasting curbs hunger and restricts eating opportunities to a smaller window of time and consequently decreases overall calories consumed.15 Although intermittent fasting may decrease body weight and/or body fat percentage, it holds numerous risks and disadvantages for athletes.
A common practice in intermittent fasting is to extend the nighttime fast from sleep, then allowing only a 4- to 12-hour window for eating at the end of the day. Consuming enough calories during this time frame can be a challenge, and avoidance of optimal windows for pre-exercise, during, and post-exercise fueling would cause performance and recovery detriments. For optimal recovery from exercise, athletes should consume carbohydrate and protein within 60 minutes after exercise. In the first 2 to 4 hours after workout, muscles are able to store glycogen more readily, while the introduction of protein switches the body from muscle breakdown to synthesis.18,19 Rehydration from exercise may also be impaired during intermittent fasting. As with calorie consumption, the limited time frame for consuming foods and fluids will make it difficult to drink enough liquids to rehydrate.
A gluten-free diet eliminates the protein (gluten) found in wheat, rye, barley, and triticale. Gluten-free diets are medically necessary for those with celiac disease or a nonceliac gluten sensitivity. Many nonceliac athletes believe that avoiding gluten improves competitive performance.19 There is no evidence-based research that a gluten-free diet is “healthier” or produces increases or decreases in sport performance.20,21 Gluten-free diets may be lacking in protein, fiber, iron, and vitamins while being higher in sugar and fat.20
Avoiding gluten can lead to an emphasis on consuming fruit, vegetables, proteins, and gluten-free whole grains. As diagnosis of celiac disease and gluten intolerance has increased, there has been growth in the availability of healthy and unhealthy gluten-free foods. However, athletes traveling for competition may still have issues with availability of gluten-free foods. Gluten-free foods also tend to be more expensive than gluten-containing counterparts. It may be difficult for athletes to reach carbohydrate needs with the elimination of gluten-containing foods.20 Many carbohydrate foods recommended to athletes, such as bread, pasta, cereals, granola bars, etc., contain gluten.
- See the whole person—not just the athlete. Healthy growth, maturation, and development should be the first priority, but this may not be the teen's first priority. Consideration should be made to how these physical changes are influencing self-esteem and sense of value.
- Know who does the shopping and preparing of meals and include him/her on any nutrition education.
- Do not assume nutrition knowledge is at any certain level. Parents, media, peers, and coaches are often the main sources of nutrition information for this population, and this information may not be evidence-based.
- Advise teens to eat 3 meals plus 2 to 4 snacks daily.
- High-fat, sugary foods should be limited, but not restricted (eg dessert 3x/week).
- Hydration should be an all-day event, not only during training.
- If weight loss is indicated, gradual weight loss or weight maintenance is the goal as they (adolescents) are still gaining height and can grow into their weight. A referral to a registered dietitian should be made to achieve this goal.
- If an athlete is following a “fad” diet, benefits, disadvantages, medical necessity, reason for use, and understanding should be addressed.
- Keep changes simple and link any nutritional education to performance as a motivating factor. For example, how can changing food choices and food timing boost performance.
- Take baby steps when advising more healthful, nutritious choices, so the changes seem more do-able. For example,
Take a positive approach with positive reinforcement and praise. His/her diet still may not be where you would like to see it, but if he/she is making changes in the right direction that should be acknowledged.
- • Soda → 100% fruit juice → low-calorie flavored water → water
- • Potato chips → baked chips → pretzels or baked whole grain crackers
- • Fast food 4 times per week → 2 times per week
- • Lunch out with friends daily → lunch out 3 times per week with 2 packed lunches
The author specially thanks Dr Alison Brooks, University of Wisconsin—Madison, Associate Professor Department of Orthopedics Division of Sports Medicine and Sarah Van Riet, MS, RD, CDE, University of Wisconsin Health.
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