"Mini-Adults"?
Whether you are a young athlete yourself or someone working with young athletes, it is important to understand growth and development and how this affects performance and injury risk in sports.
Chronological vs. Biological Age
Both chronological and biological ages are important to consider when considering sport, development and performance.
Did you know that...
...adolescent can often find that they perform worse when they grow a lot?
Chronological Age
Say two 13-year-old athletes were born in the same year, but one was born in January and the other in December. This means there is almost a year difference in calendar year, or chronological age, between them. This also means that those born early in the year may have a physiological advantage, simply because they are older and have progressed further both in growth and maturity. Due to being some months older, they also may run faster and jump higher than their peers born later in the same year. This simply comes from being more developed due to their earlier birthdate, and often referred to as the relative age effect (RAE).
Biological Age
Children and young people mature and develop at very different times and rates. There are also significant differences between boys and girls regarding puberty, growth, and maturation. The average starting age for puberty for girls in Norway is around 10 years, while for boys, it is about 2 years later. However, there are large variations in these numbers, and it is therefore important to understand that there most often are large differences between young people born in the same year. In fact, within the same age group, there can be up to a 5-year difference in biological maturity! Biological maturity affects body dimensions, body composition, and body proportions, which significantly impacts sports development and performance during adolescence.
A Brief on Puberty
Hormones
Hormones largely initiate and influence growth, maturation, and development during puberty. Hormones act like the body's "mail carriers", sending signals throughout the body to accomplish various tasks. There are many different hormones, but the most important to know about regarding puberty are sex hormones and growth hormones. These hormones "explode" during puberty, when their release into the blood increases dramatically. This affects all parts of the body including the brain, the skeleton, muscles, and tendons, resulting in a body undergoing significant reconstruction!
Puberty
During the first part of puberty, the "growth spurt" occurs. This is the phase where adolescents grow the fastest. For girls, the growth spurt starts around 11 years of age, while for boys, it starts somewhat later (at around 13 years). The growth spurt lasts, on average, about 2 years, regardless of gender.
During this period, the skeleton grows a lot and faster than muscles and tendons in the beginning. Arms and legs grow first, followed by the rest of the body. This naturally makes adolescents a bit clumsier during this time, and their performance development may stall or even decline for a period. It’s good to know that this is completely natural – and even very common.
The Skeleton
Adolescents are particularly prone to fractures when they grow a lot because:
1.The bones in arms and legs increase in length before it increases in width.
2. The skeleton also temporarily suffers froma reducedbone density because bone mineralization (production of new bone) may lag behind the increased length growth (despite overall increased bone mineralization during puberty).
3. Growth zones in the skeleton are especially vulnerable and prone to injury because they consist of cartilage which is “softer” compared to bone
Good nutritional status is crucial for normal bone development. It is especially important to maintain adequate and continuous intake of calcium and vitamin D throughout puberty and adolescent years. Most of the bone mass is built during puberty, and it is especially important for girls to remember this to reduce the risk of osteoporosis or stress reactions or stress fractures. Visit Sunn Idrett’s website: sunnidrett.no, to learn more about how to eat enough and smart to stay healthy and strong during this vulnerable period.
Muscles and Tendons
Puberty is a vulnerable roller coaster in many areas. Before puberty, there are small differences between boys and girls in terms of performance development and physical performance. During and after puberty, this changes, and the differences between boys and girls increase in terms of both strength, endurance, and power. Boys experience a significant increase in the sex hormone testosterone, often leading to rapid performance improvements due to increased muscle mass. This also means that tendons and ligaments are subjected to more stress during this period because they do not develop as quickly and are exposed to greater loads as a result of both increased muscle mass and length growth.
Girls typically experience a relative decrease in strength, which doesn’t mean they get weaker but that they naturally gain more fat mass and become heavier during puberty. This is the way it is supposed to be. This comes from higher levels of the female sex hormone estrogen. During this period, it is challenging to maintain the same degree and form of load as before. Training should be adapted to the body’s development, and it may be wise to differentiate more between boys and girls during puberty. Extra focus on strength training, stability, technique, and motor skills can help develop strength in parallel with increased body weight, while tendons and muscles are subjected to gentler loads. Good technique and gradual progression in load are keys to reducing injury risk, which we know is particularly high during puberty, especially for girls.
The Brain
The brain develops throughout life, including during puberty. Significant "reconstruction" occurs to better adapt to each individual's life. Different parts of the brain develop at different rates and times. Early changes and adjustments in the teenage brain typically occur in the area that controls movement and motor skills. This provides a good foundation for practicing and drilling various movements and techniques from early puberty. This is also why it’s important to practice injury-preventive movements from an early age.Simply put, the teenage years are a very useful time to learn skills you will use for the rest of your life.It is smart to take advantage of in sports performance development – neuromotor learning from early puberty is beneficial, and developing technical, tactical, and neuromotor skills is advisable from early puberty due to these early brain changes.
Other typical changes in the brain during puberty involve the ability to think rationally. As many experiences, the teenage brain is often more driven by emotions and feelings than rational thinking. The reason adolescents are more emotionally driven and impulsive is that the frontal lobe isn’t fully developed until well into the 20s! The frontal lobe controls, among other things, the ability to consider consequences, plan, and resist temptations. This means that adolescents do not have the same capacity or tools to think and evaluate all situations as an adult would, simply because the part of the brain that acts as the conductor for "reason" and makes these decisions isn’t fully developed. This may also explain why many young athletes take more risks and are less concerned about possible negative consequences. It may also contribute to the increased risk of injury during adolescence, both generally and in sports.
You can read more about growth and development and get practical advice for the development of young athletes in Norwegian here.
