top of page

Adolescence and Muscular Development

Young Man doing Incline Bench Press

During the pubescent period, a period that typically lasts three to four years, teens will gain approximately 20% of their adult height (regardless of their gender). With this growth in height comes a nearly 50% increase in body weight with height increase certainly accounting for a large percentage of that, but the rapid development of lean muscle mass is also at play. All of this, according to Live Strong.

Baseball Pitcher

According to, muscle development is influenced most by three main factors: heredity, nutrition and muscle building exercise. Not surprisingly, teens that play sports, lift weights and work out in other ways, become more fit and build greater muscle mass.

As we walk through this growth, I want to cover 4 areas that parents should know about and guide their young athletes through. These areas are diet, proper training, supplementation, and misconceptions.


One Reuters report shows that boys between 14 and 17 years old can and will eat a lunch of up to 2000 calories if its available. Live Strong recommends against allowing them to do this however, suggesting that 5-6 smaller meals per day will do them more good, and keep them from cramping during sporting activities. Spreading the digestive cycle to more smaller meals is highly recommended.

Fats Carbs Proteins

By now, we all know that our food intake breaks down to 3 specific components: Proteins, Carbohydrates, and Fats. A balance of these produces the best results in muscular development. A common problem is overloading on carbohydrates, which are certainly needed. But Carbohydrates are stored in the body to be used as fuel when needed. Too many carbohydrates and your teen will have more than they use which leads to body fat problems.


Weight training is the most recommended form of training for muscular development. The concern with weight training will always be one of young people working to lift heavy without having built proper form and muscular recruitment patterns.

The most recommended movements for muscular development are squats, deadlifts and bench presses. These lifts work the large muscle groups. They also spur the body to develop muscle mass (when supported by a proper sleep and nutrition program).

Deadlift Technique

Attempting any of the three without supervision or assistance can do more harm that good. At St. Louis Youth Performance, athletes are never turned loose to lift heavy until they have received hours of coaching and instruction. Only after our athletes have shown proficiency with any lift, are they allowed to train with substantive weight.

Concerns that come with heavy weight training include damage to growth plates (if performed before growth plates have hardened), tendinitis, and muscle strains. Of course the list of potential injuries is much longer, but the occurrence of injuries of these other types drops off quickly.


Supplement Bottles

I hate giving ages as guidelines because all kids develop at their own pace, but as a general rule, supplementation should consist of protein only for teens under 16. Good sources of protein are out there in several forms, but I prefer a good quality whey protein for youth. Typically, a good whey can be purchased for between $1 & $2 per daily serving. As for protein intake, an adolescent as a rule of thumb should take in 65-80% of their body weight in protein grams daily to support the development they are after.

I discuss protein and adolescents in more detail in this article.

Deeper into puberty, boys can begin to work with other supplements. Those most commonly recommended include creatine and several amino acids. Personally, I never recommend anything in this area as I'm not personally knowledgeable enough to tailor programs here. I recommend discussing these types of supplementation with your child's pediatrician or sports doctor.


Weight training stunts growth. This one has been around for many years. Somehow, people believe that if you lift, you compress the bones and they won't grow. Nothing could be further from true, as I discuss in my article on puberty and bone development.

Weight training makes girls bulky. While "Body Building" is designed to increase muscle mass in boys or girls, it involves programming that is focused on increasing muscle size. Typically, we won't see a female body respond to weight training in such a way that they become bulky. Bulk is supported by testosterone, and the female body doesn't produce this hormone in a quantity that would normally support the development of mass. Scratch it off of your list of concerns.

Muscle if you don't use it, turns to fat. Biologically impossible, muscle is one type of cells and fat another. Cells don't convert from one type to another. You can see a reduction in your muscle mass and an increase in fat cells in the body, but one never becomes the other.

Featured Posts
Recent Posts
Search By Tags
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square
bottom of page