This is up for debate with everyone in my industry. My view though is a little different then most. I thank my oldest son for this. Growing up in Alabama till I was in third grade and then moving to Iowa I noticed two major differences in the culture. Now in Utah I can see why the SEC is in general the best football conference. I was able to play tackle football and baseball before I started elementary school. While in Iowa we didn’t really start till we were in 7th grade. No real fundamentals were being taught yet.
Why am I stating this with developing a better athlete? Look how far ahead Alabama was in skills (Fundamentals) then Iowa. Many years ahead. The same thing goes with athletic development. We arn’t saying lets max out at age 2 or 3 on weights. What I’m saying let’s teach kids fun and intersting things at a younger age so that they can build upon them when they reach the age to fully enhance those skills.
Here is a major example my little boy who is three likes to jump run and pick things up. So this is what I started to do I placed cones in my front yard and we ran angle drills to work on small agility drills my son loved it and he was doing stuff like it already I was just to able to harness his energy into this specific drill.