1. You keep getting selected for rep teams based on your physical talent, not because of the work you have put into developing your athleticism.
Not entirely your fault, obviously, you were given a gift of size and strength, coordination, and control ahead of your years and using that to excel in youth sports is entirely understandable. However, the mistake you will make is believing that will last your lifetime. Being the best athlete in year six does not mean you will be signing an All Blacks contract when you are 18. There is no guarantee that the athleticism you have now will persist to the same degree through puberty if you experience a significant growth spurt. You should not expect you will be able just to plow through that growth spurt with the same ease you now strike a hockey ball, sprint across the finish line in first place, or win the basketball game for your team.
From my experience, the acclaim you receive at a young age will either give you a false sense of accomplishment and either reinforce an "I don't need to prepare for sport" mentality, or you will swing to the other end of the spectrum and start doing too much. In other words, you will either do nothing and keep pushing your body to a level it will struggle to keep up with, or you will start doing training that is beyond your capability and capacity, and that too will contribute to early breakdown.
2. You like to play more than you like to train.
Just let them play. It is all about participation. Just let the kids have fun playing they don't need to prepare in such a structured way it's not high-performance sport. Those statements echo through the halls of schools, community centers, and sports clubs worldwide. In my opinion, those mental models are not enough to ensure kids turn childhood participation into a lifetime of physical activity. There is evidence that just playing sport can contribute to a high rate of kids dropping out of sport and getting injured. The evidence points to the "winning at all costs" mentality distracting youths from respecting the process of preparation for sport and becoming more athletic. Failing to give kids an opportunity to learn how to prepare for sport and competition in a manner that is within their physical competency and capacity is what can undermine a positive sporting experience and could comprimise the longevity and physical development a young athlete may experience.
Sport is awesome! I have made a career in sport and could not think of anything better. It is during my career that I have realized that structure and preparation do not rob a child of casual play, exploration and physical development, it promotes it. Kids these days do not do as much incidental running, climbing, jumping and playing. Therefore, they do not progressively develop as kids 10-30 years ago did. Which is why structured practices that are supported by warm-up and cool-down programs that strive to mitigate injury and improve athleticism are so essential for the health, safety and continued physical literacy of our youth these days.
Kids should have the opportunity to explore new physical challenges and participate in a variety of sports. The sports organizations that provide a better more structured experience for kids give them a real opportunity to grow and develop physically and mentally as a result of playing sport.
3. You think playing a bunch of different sports will develop your athleticism.
Wrong! For two primary reasons. The first reason I mentioned above, sport today prioritizes competition over development; sport should be used as a vehicle to teach kids how to use their body and provide children the knowledge and expertise to grow and develop themselves athletically. Short youth sport seasons that focus on preparing for competitions regardless of a childs age, time in the sport or athletic ability. Along with a limited number of training sessions per week that give kids an opportunity to develop in a progressive and safe manner have been identified to be mechanisms of youth sport injury. Lastly, coaches need more education on movement in general and in a manner specific to their sport. Structured warm-up, training and cool down protocols that are based on research and practice-based evidence should be made readily avaialbe to all coaches and parents.
Second, the physical demand of basketball is different to the physical demand of swimming. I have heard "my son or daughter swims for fitness to help their basketball, rugby, etc." The reality is swimming can be good cross training for athletes that participate in ground-based sports. However, as I stated above, too often the focus is on the 'outcome' of winning a competition or season, there is less emphasis on structured, progressive physical development based on a child's developmental age and personal situation. Personalizing a program for a child is not as complicated as one may think. Most kids have similar physical development issues. Therefore, structured warm-ups, training plans, and cool downs that focus on progressing children based on their movement competency and capacity and the demands of the sport can help ensure the physical loading children experience during sports participation contributes more to their performance and development and not the mechanisms of injury.
The body moves toward physical strength and away from physical weakness. For example, the structure and function required to jump in basketball can be achieved in a variety of ways. Some ways are good and will contribute to performance and not injury. Other ways are not good that will also contribute to performance AS WELL AS injury. The problem is the difference is not intuitive or commonly understood. A coaches primary responsibility is to teach the skills of the sport and to get an athlete ready to compete. Kids are rewarded based on how high they can jump, how hard and accurate they can pass, and how well they can shoot. Regardless if the strategy they use to accomplish those movement tasks is a injury mechanism. If the child scores, or runs / swims fast then mission accomplished. Which is why playing and training for basketball does not necessary make you a better athlete. Every sports skill can be linked to a foundational movement pattern. It would be great if sport skills where linked to their fundamental pattern and that was then taught to coaches as part of their foundational education. What complicates this, even more, is that kids are very flexible and hypermobile, which affords them the ability to move poorly without suffering the immediate consequences. Going from one sport to the next and the next in a given day or week forces the child to be in a constant state of shock trying to adapt to the demands while never really having an opportunity to develop the physical readiness required to handle those demands. Which is why those kids that are physically more mature (i.e. stronger) do better. They can handle the demands...for now.
So what is the solution? How do I achieve athletic success? Awareness. Feel good that you get picked first and have the physical ability you do have, but don't get swept away thinking you will always have it and you don't need to train as hard as those who appear not to be as physically gifted as you are. You need to train harder and smarter. Proper warm up routines that challenge your coordination, balance and strength are a good place to start regardless of age. Next, if you have access to a movement matters program like the ones offered by Athlete Nation, prioritize your involvement in one of those programs so that as you grow and mature you develop the strength and coordination to support your athleticism. That way whatever sport(s) you do play will promote a healthy, successful life as a result of your sports participation not in spite of it.