There are two answers to this question, and the difference matters.

Earlier than most parents think for movement skills.

The American Academy of Pediatrics and Long-Term Athlete Development frameworks both converge on the same finding: kids benefit from broad movement experience starting as early as age 2-3. Climbing, throwing, kicking, swimming, running, balancing, jumping. The Mommy-and-Me class, the toddler tumbling group, the backyard ball game. All of it builds the movement vocabulary the kid will use in any sport later.

This isn’t training. It’s exposure. There’s no team, no league, no scoreboard. Just movement.

Later than most parents think for organized competitive sport.

Real organized leagues with practices, games, and roster commitments work well starting at 5-7 for some sports (rec soccer, T-ball, swim lessons), 6-8 for others (most rec basketball, gymnastics class). Travel ball, club, and competition formats: not before 9 or 10 in almost any sport, and even then with caution.

What the research consistently shows: kids who start organized competitive sport too early have higher injury rates, higher burnout rates, and no advantage in long-term athletic outcomes. The kid who plays rec sports from 5 and adds club at 11 ends up in roughly the same place as the kid who started club at 7, except healthier and more likely to still be playing at 16.

The right shape by age.

Age 2-4: free movement. Whatever they want to climb, kick, throw, splash. Nothing organized. Library story-time over scheduled sports class.

Age 5-7: introduction. One organized rec activity at a time. T-ball, soccer, swimming, gymnastics. 30-45 minutes per session, once or twice a week. Lots of free play around it.

Age 8-10: variety. Two sports across the year is healthy. Try the new thing. Add rec basketball in the winter. Drop the sport they don’t like anymore. The window for trying things narrows after this.

Age 11-12: refinement. Most kids settle into 1-2 primary sports plus a third casual one. Travel/club becomes a real option but not a requirement. Multi-sport still recommended.

Age 13-14: focus. Some kids start specializing. AAP says wait until 14 minimum. Honest read: 14 is the floor, not the ideal.

Age 15+: commitment. Specialization is reasonable for kids who want it. Even then, an off-season and cross-training matter.

What to skip.

Skip baby gymnastics where the goal is competitive readiness. Skip toddler soccer leagues that keep score. Skip the elite-track programs that recruit from age-5 classes. None of those produce better outcomes long-term, and most of them produce earlier dropout.

Skip private lessons before age 9 in almost every sport. The kid doesn’t have the body or the attention span to convert one-on-one instruction into skill at that age. Group classes work better.

Skip the rush to “get them in” early at the elite track. The competitive window opens around 12-14 in most sports. Anyone telling you it opens at 7 is selling you something.

What to do.

Find the rec league at the local park. Sign up. Show up. Watch your kid have fun or not have fun. If they like it, do it again next year. If they don’t, try a different sport. Keep the schedule loose. Keep the cost low. Don’t make it the family’s identity yet.

The kids who keep playing sports through high school are overwhelmingly the kids who started in low-stakes settings, played multiple sports through middle school, and weren’t asked to commit to anything serious before 11 or 12. The data is consistent.

Start movement early. Start competition late. That’s the framing.