“Bulking Up” For Sports?

Patient Presentation
A 16-year-old male came to clinic because his mother was worried about his desire to gain weight. He had played on a local, non-traveling, recreational soccer team for several years and enjoyed it. Over the past 6 months his friends, who included varsity athletes in several sports, had started to do more weight lifting with their teams. In addition to their sport specific training, this group of young men were all doing weight training twice a week together. The patient was also doing 2 more sessions/week by himself. He had increased his protein intake by “eating more meat” and was taking protein supplements. He was also restricting his diet by consuming almost no dairy products or fruits or vegetables. He ate minimal carbohydrates. He wanted to “bulk up” so that he would be more competitive at soccer and to be like his friends. He was not planning on doing any other competitive sports, nor competitive soccer. He would run 2-3 miles on days he was not lifting weights. He had always been on the heavier side in weight with a BMI around 75%. When asked how he felt, the teen said that he liked being with his friends. He said that he was learning more about weight lifting and had been slowly increasing the amount of weight he lifted. “My running has gotten slower though I notice. It’s taking me longer to run the same loops,” he offered. His mother stated that he seemed tired a lot of the time and was crabbier. “He’s also not getting enough sleep,” she complained.

The past medical history was non-contributory. The family history showed that his father was obese and short. He walked and swam for exercise. His mother was average-sized and walked and bicycled for exercise.

The pertinent physical exam showed his vital signs to be normal. His height was 171 cm (25-50%) and his weight 68.2 kg (~50-75%), BMI was 24 and abdominal circumference was 99 cm (>90%). His BMI was trending upward. He was Tanner V and had been the same height for 18 months. The rest of his physical examination was normal.

The diagnosis of a young teen with abnormal weight gain was made. The pediatrician began counseling him by emphasizing the positive aspects of exercising, being part of a friend group, and persistence in trying to achieve a goal. However he also emphasized that several behaviors were not helpful including restricting food, using supplements and poor sleep habits. “Exercise and weight training can be good but you have to do it smart. You can have some more protein along with weight training to increase muscle, but it has to be part of overall good nutrition. That means eating dairy products and some fruits and vegetable and even carbohydrates. Sleep is actually really important too for your overall health but also for your body to use the protein you are putting into it. Sleep is your rest period and the body can also try to build the muscle. Do you like the weight training?” he asked. “Yeah, I like being with my friends and I like how I feel stronger now than I did. I’d like to do better at the running because I’m going to start back with soccer soon,” he said. “Okay, would you like to talk with one of the dieticians who can help you to figure out how much protein and everything else you need to keep growing and being able to do soccer and weight training?” he asked. The teen agreed to see the dietician and also agreed to stop using the protein supplement.

The patient’s clinical course a few weeks later showed he had stopped taking the supplement, had had an average soccer season, and was still weight lifting.
“I think I hurt myself for soccer, but I am still lifting 2 times a week with my friends and we’re doing it at school now with the trainer. I’m eating better but spring soccer will be here soon, and I’ll be stronger with my running by that time,” he said.

Athletes, whether recreational or competitive, who participate in weight sensitive sports commonly gain or lose weight to achieve a particular body type or to improve performance. Athletes in duration or aesthetic sports (such as distance running, diving, dance, etc.) attempting to lose weight to be able to move the body against gravity better. Sports that emphasize strength and power including combat sports (such as football, wrestling, mixed martial arts, body building, etc.) often have athletes attempting to gain weight and lean muscle mass to improve performance. This is felt to increase the strength-to-weight ratio. Weight class sports which can include some combat sports and others such as rowing, can cause some athletes to roller-coaster between losing weight to be able to compete in a lower weight class and then gaining weight back. Rapid weight loss and rapid weight gain can have detrimental effects both acutely and long-term on the athletes. A systematic review of rapid weight loss and gain in combat sports participants found that there is poor data on rapid weight loss, and the rapid weight gain is “…influenced by the type of sports, competition structure, and recovery duration.” “[A]thletes are able to exploit the [competition] rules to compete up to three weight categories higher than at the official weigh-in.” The studies mainly involved male athletes and there was little data for females. Sports with the least amount of time between weigh in and competition, and the least time between competitions tend not to engage in rapid weight loss and gain.

Rapid weight loss can cause athletes to feel fatigued and weak, feel disoriented, anxious, dizzy or feverish, and having epistaxis and headaches. It has also lead to death in some high profile cases. Rapid weight gain can cause problems with maturation and growth and disordered eating, plus problems in immune response, endocrine, cardiovascular, renal and thermoregulatory systems. Athletes fail to realize that after 2-3 days of dehydration that is often used to “cut weight,” it can take 48 hours to replace intracellular fluids. Inadequate hydration decreases aerobic and anaerobic performance with aerobic performance being more affected.

“Athletes rely most heavily on their coaches and teammates for advice on making weight, and qualified professionals (i.e. dieticians and physical trainers) are among the least influential.”

Learning Point
“[S]ports performance may be the best indicators for an athlete’s optimal body composition and weight at his or her developmental age.”

According to the American Academy of Pediatrics healthy weight gain should:

    Be gradual weight gain that is muscle mass not increased fat

      Boys up to 0.5-1 pound/week
      Girls up to 0.25-0.75 pound/week
      Weight gain should be up to genetic potential

    If maintaining body weight and eating the recommended amount of protein, the athlete can

      Consume 300-500 kcal/day above baseline intake
      Consume extra 14 g of protein/day (or 1.5-1.8 g protein/kg/day)*
      Do strength training (this helps to incorporate the protein into muscle mass)**
      and should get adequate sleep

*As a comparison, 7 grams of protein is 1 egg, 1 tablespoon peanut butter, 1 ounce of chicken, 1/4 cup cooked beans or tofu

** The AAP does not recommend skeletally immature children or adolescents do body building, power lifting or maximal lifts.
“[S]ports performance may be the best indicators for an athlete’s optimal body composition and weight at his or her developmental age.”

Questions for Further Discussion
1. What are indications for consultation with sports medicine?
2. What are indications for consultation with a dietician?
3. How much exercise should children and teens do? A review can be found here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for these topics: Body Weight, Diets, and Sports Fitness.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports. 2019;7(7). doi:10.3390/sports7070154

Matthews JJ, Stanhope EN, Godwin MS, Holmes MEJ, Artioli GG. The Magnitude of Rapid Weight Loss and Rapid Weight Gain in Combat Sport Athletes Preparing for Competition: A Systematic Review. Int J Sport Nutr Exerc Metab. 2019;29(4):441-452. doi:10.1123/ijsnem.2018-0165

Carl RL, Johnson MD, Martin TJ, Council on Sports Medicine and Fitness. Promotion of Healthy Weight-Control Practices in Young Athletes. Pediatrics. 2017;140(3). doi:10.1542/peds.2017-1871

Carl R. Healthy Weight Practices for Child and Adolescent Athletes. Pediatr Ann. 2019;48(7):e286-e289. doi:10.3928/19382359-20190617-02

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa