So what are the 3 most important things for athletic development (not the only things, but the most foundational for sure)? Honestly, that is a lot simpler than we make it out to be. There are a lot of theories out there, most of which do not work. My favorite, is that you need to get bigger or build muscle. That is almost always WRONG. The very first, and most important thing is to development good relative strength. Relative strength is your strength compared to your body weight. For example, lets say that you are a football player. Would you rather get hit by the guy that weighs 300 pounds and squats 400 pounds or the linebacker that weighs 190 pounds and squats 600 pounds. Most would say the smaller guy. It is really easy to forget the force=mass X acceleration, not just F=M, that is until you hit something that is moving really fast. For instance, a 140 gram baseball moving at 100 mph hour can shatter bones and cause severe trauma. Getting bigger will slow you down unless you manage to maintain or improve your relative strength. When I was playing high school football we did a lot of Bigger-Faster-Stronger programs. I got bigger and stronger but not faster. Actually I was the strongest guy in my school, and one of the slowest. I ran a wimpy 5.6 forty at my worst (225 pounds). Post grad school, I ran a 4.7 at 215 pounds and was about 20% stronger.
The next thing is strength balance, particularly between the posterior (back) and anterior (front) chain. Most people are front side strong and back side weak. Balance is important for several reasons: most forward propulsion is a result of posterior muscle force, the nervous system will limit front side strength in the presence of backside weakness, balance reduces injury risk. Generally speaking, the posterior chain should be at least 60% as strong as the anterior chain. Honestly, I prefer more like a minimum of 80%. Actually, most anterior strength needs to be eccentric for better change of direction. Granted, eccentric and reactive strengths are important all around.
Lastly…confidence. I have seen some very athletic people that make poor athletes because of two things: not enough confidence and thinking too much (which typically come together). The first thing is to realize both of these things. The second is to learn to “turn off your brain” and just react. That takes practice, and in some cases, a lot of “stop thinking!” from the coach. The next thing is to practice each specific athletic movement or skill so much that they become completely natural. That takes about 5000 hours of practicing a skill correctly before it becomes instinctive. Note that I said “correctly”. Remember that practice makes permanent, not perfect. Perfect practice makes perfect permanent. So it is important to slow a motion down and practice it correctly, then speed it up to full speed over time. In other words, don’t practice a one step change of direction at full speed unless you can do it at 90% full speed first. For complex motions, a clean a jerk for instance, each part of the motion must be trained separately, then put together, then sped up one part at a time.