A plain-language, research-backed guide to physical development from first-ball through the pros. Built on what the science actually says, not on what is trending. This is the thinking behind every DugoutLab training resource.
Train the athlete before the sport. Between roughly ages 7 and 13, the best thing you can do for a young player is build a strong, coordinated, multi-sport mover. Bodyweight strength, jumping, sprinting, throwing, catching, rotating, and playing many sports. Heavy weights, max-effort lifts, and bodybuilding splits do not belong in this window. What does: high-quality movement, light rotational work, and an adult who watches how the kid moves.
Readiness beats birthday. Two kids the same age can be two years apart in physical maturity. Train the body in front of you, not the number on the form. Form earns the load, every time.
These do not change from age 6 to the pros. Only the dose changes.
Maturity, not a birthday, sets the program. Progress on what the athlete can control with clean form. Earlier is not better. Ready is better.
Enjoyment is the single biggest predictor of whether a kid keeps playing. Bored kids quit. Variety and play drive development as much as any drill.
Master bodyweight patterns before adding any external weight. Squat, hinge, push, pull, brace, land, carry. Quality reps beat heavy reps.
Five stages from first-ball to the pros. Ages are guides, not gates, and they shift about a year or two earlier for girls. Tap any stage to see what to build and what to avoid.
Development is mostly about not breaking the athlete. These three matter more than any drill.
During the fastest growth phase (Peak Height Velocity), bones grow faster than muscles and tendons. Kids get temporarily clumsy and more injury-prone, especially at the knee (Osgood-Schlatter) and heel (Sever's). Signs: a sudden height jump, recent shoe-size change, new complaints of knee or heel pain. The right response is to lower the jumping and high-impact volume, lean into mobility and technique, and never push through joint pain. Strength windows open after the spurt, not during it.
The research is consistent: sampling many sports through about age 13, then specializing around 14 to 15, is associated with longer careers and fewer overuse injuries. Multi-sport athletes reach the top at least as often as early specialists. Telling an 8-year-old to play one sport year-round is bad for their athleticism and their love of the game.
Female athletes mature earlier and carry a much higher ACL injury risk, and are more vulnerable to under-fueling during growth (known as RED-S). Evidence-based neuromuscular warm-ups that teach soft, aligned landings cut ACL injuries dramatically and should be standard from late childhood on. Enough food, enough sleep, and managed load protect both performance and long-term health.
This playbook is about athletic development: strength, power, speed, movement. It does not cover throwing or pitching programs. Throwing volume is the highest-risk variable for a young arm and has to be coordinated with the athlete's actual team and game schedule by someone qualified, watching that specific athlete. We keep it separate on purpose.
Every recommendation here traces back to recognized position statements and peer-reviewed research. The full reference list:
Educational resource only. Not medical advice. This page explains general principles of youth athletic development. It is not a personalized training prescription and does not replace a qualified strength coach, athletic trainer, or physician who can see your athlete. Before starting any program, especially around a growth spurt or any pain, check with a professional. Some evidence here is strong and some is emerging; we have tried to be honest about the difference.