Growth and Development for the Young Athlete

By Bruce Cohn
Concord Journal, November 2002
 
One of the questions I am most frequently asked about in my work as strength and conditioning professional is about the affects that training has on a developing adolescent’s body. These questions range from young athletes wanting to know if training will make them bigger to parental concerns about conditioning interfering with growth. I will attempt to try to answer some of these and other issues in today’s article.

We are only beginning to understand the interplay between genetics and environmental influences. Most of the differences that we see in teenagers’ growth can be attributed to genetics. The growth that we see following puberty is most often in limb length; the broadening of chest and shoulders follows later. That having been said, we know that by the age of 14-15 kids who are active have wider shoulders than hips owing to muscle mass development. Fat tissue in these young athletes has more mitochondria than are found in the fat tissue of inactive teens. Since mitochondria are the “energy factories” of the cell this has major implications for the burning of calories and avoidance of obesity. Teenagers who are active have a 40% higher basal metabolic rate (calories used to maintain bodily function at rest) than their inactive counterparts and experience a 15-20% increase in basal metabolic rate for up to 10 years after their participation.

In previous articles I have discussed the varied benefits associated with training. These include development of neuromuscular connections leading to increased speed and strength as well as the growth of fat free mass, primarily muscle. I always try to emphasize the relative importance of the former to every athlete with whom I work. The development of muscle mass reflects the interplay between training, distribution of muscle fiber type which in large part is genetically pre-determined and neuromuscular and endocrine controls within each individual’s body. During adolescence, girls add 1.8% fat free mass and 2.1% fat mass growth for each centimeter of growth in height. Boys, on the other hand, add 2.8% fat free mass to 1.9% fat mass growth for each centimeter of growth in height. Since girls usually reach puberty before boys it is essential that they do strength training during the growth spurt that follows.

We will always see individual differences in how young athletes respond to a strength and conditioning program. An understanding of growth and development patterns must inform such a program. Our emphasis on core training and functional movement patterns is geared towards helping the young athlete integrate body control with body growth. At the same time that we are enhancing a teen’s neuromuscular development we must explain the individual differences in muscle growth that each will experience. In this way we can truly say that we encourage each athlete to be the best that he or she can be.

Bruce Cohn is the Strength and Conditioning Coach at the Middlesex School in Concord. He runs FIT-TO-GO Total Sports Conditioning and is a nationally certified Strength and Conditioning Specialist. Bruce can be reached at 781-316-0061 or brucegym@rcn.com.