Different athletes have different needs. Some athletes need more activation than others, some are tight as drums and need to work on mobility, some are biomechanic train wrecks and need an overhaul, there are even kids that have grown too fast and forgotten that their hands are connected to the rest of their body. This is where a strength and conditioning and playing multiple sports throughout the year becomes pivotal in the development of an athlete.
We know that specialization at an early age is detrimental to long term performance and health. Athlete's simply break down when they pitch too much. The best player on the team pitches the most innings and games during the year and gets ruined before his time.
Until 15-16 years old kids need to be exposed to as many sports and physical activities as possible, especially before the age of 12. The need to wrestle, play baseball and football, ride a bike, ski/snowboard, skateboard, roller skate and/or rollerblade, play basketball (although I hate to admit it), go swimming and learn to do a flip, they need to run around, climb trees, get hurt, have a physically demanding job like construction or landscaping, etc...
They need to be active and it doesn't have to be competition or even organized. Play catch in the backyard, hang a rope from a tree, sneak onto a driving range at night w/ a baseball bat steal some balls and see how far you can hit them. Obviously the last one is a stretch.
But in all honesty I grew up where every time you stayed at a friends house you had wrestling matches after dinner every night. Why do you think Iowa is so good at wrestling. This was great for our coordination, body positioning, and all around real world strength, the basis of any great athlete.
Get your kids moving.