The question of when a person should begin going to the gym is less about a specific birthday and more about physical development, maturity, and safety. Starting a structured fitness routine prematurely without proper guidance can increase the risk of injury in developing bodies. The primary focus for any age group entering fitness should be injury prevention and mastering correct movement patterns before introducing significant load. Gym activity must adapt to a person’s readiness, progressing from fundamental skills to independent, heavy resistance training.
Building Movement Skills Before the Gym (Ages 6–12)
This age range is foundational for developing coordination, balance, and body awareness, which are crucial precursors to formal training. Heavy, structured weightlifting is inappropriate as the goal is not yet muscle hypertrophy or building bulk. Activities should prioritize general physical literacy and motor skill development, making participation in sports a highly effective approach.
Children benefit from exercises that use their own body weight as resistance. Simple movements like push-ups, squats, lunges, and controlled jumping drills establish a mind-body connection. These functional activities prepare the musculoskeletal system for more complex movements later, while also strengthening bone density. The American Academy of Pediatrics suggests that children as young as eight can safely begin strength training, provided they can follow instructions and maintain good form.
Resistance training at this stage should involve low resistance and high repetition, focusing on technique rather than intensity. While the common fear is that lifting weights will damage growth plates, studies indicate that proper, supervised training is safe and that growth plate injuries are far more likely to occur during recreational sports. The focus remains on skill development and enjoyment.
Starting Supervised Resistance Training (Ages 13–16)
This period marks the transition into adolescence, where hormonal changes begin to allow for meaningful increases in muscle mass and strength. The skeleton is still maturing, making supervision mandatory for any structured resistance training program. Growth plates, or physes, are still open and are made of cartilage, which is relatively weaker than the surrounding bone.
While resistance training does not stunt growth, excessive or incorrect loading before the growth plates have fully closed can potentially lead to injury. Training must transition slowly from bodyweight exercises to light resistance, such as resistance bands, light dumbbells, or child-sized machine weights. The priority must remain on mastering form for movements like the squat, hinge, press, and pull before any significant weight is added.
Supervision by a certified professional, coach, or knowledgeable parent is necessary to ensure proper technique and prevent training to failure or attempting a one-repetition maximum (1RM). Programs should employ submaximal loads (8 to 15 repetitions with good form), performed two to three times per week. This methodical, supervised approach maximizes strength gains while mitigating the risk of overuse injuries that can arise from rapid growth spurts and poor coordination.
Transitioning to Independent Adult Fitness (Ages 17 and Up)
By age 17, most individuals have achieved sufficient skeletal maturity (growth plates are largely fused), allowing them to handle traditional adult programming and progressive overload. This age represents a shift from foundational skill acquisition to maximizing performance and strength. The body is now better equipped to handle the forces generated by heavier loads and more complex movements.
The focus shifts from growth plate injury prevention to minimizing common overuse injuries and ensuring training is effective. Individuals can now safely incorporate higher-intensity training, including heavier weights and complex, multi-joint movements like deadlifts, barbell squats, and overhead presses. These exercises are highly effective for building strength but require excellent form, which should have been established during the earlier, supervised phase.
While full-time supervision is no longer required, seeking professional guidance is still recommended for designing advanced, periodized programming aimed at specific strength goals. Skeletal muscle adaptation remains high throughout early adulthood, making this an ideal time to build a solid base of muscle mass and bone mineral density. Establishing consistent, independent training habits now helps counteract the age-related decline in muscle mass that typically begins around age 30.