On the “Gym Rules” sign in most gyms, you’ll see “No children under the age of X”. This reinforces the misconception that children or teenagers should stay away from the weights room, which isn’t strictly true.
In fact, the signs are usually there because of a supervision issue - constant vigilance is required to make sure Junior isn’t doing damage to the equipment or himself - and because kids tend to be fairly distracting.
It has nothing to do whether kids CAN get involved or not. Teenagers on competitive high school teams perform resistance training under proper supervision of a strength coach or personal trainer.
It’s a question of style; the approach is geared towards explosive bodyweight movement, rather than pure strength building. There are some safety concerns at play here, but in youth sports, generally speaking, it pays to be faster than your opponent.
Building strength and muscle mass is more appropriate for contact sports, which tend to be taken up in later teens and young adulthood. Puberty will also dictate whether and when a younger athlete focuses on speed over size. Testosterone levels massively influence muscle gain. Stage, rather than age, of physical development is a good indicator of the type of training kids should be doing.
Most children go through a “growth spurt” where they seem to shoot up six inches all of a sudden - after which, it’s back to a slow crawl of centimetres. Before this, overloading their growing frames with heavy exercises is not typically recommended. As they grow, this load can be increased; weight goes up with height, as it were.
Teenagers have to take particular care with technique. Posture takes priority, form is the foremost focus. Hip tilt and core bracing are also important. Younger adults have a higher risk of long-term injury if not introduced to proper training techniques. Teenagers should train smarter, not harder. For example, a young man deadlifting 75kg already has an advantage over his age group. Why risk lifting 150kg with poor form?
It makes sense, in fact, for children and teenagers to learn proper strength training before they’ve had a chance to pick up bad habits.
However, a teenager will not learn these movements through personal trial and error. An experienced personal trainer should be consulted.
Mobility is one factor at play. Younger humans are generally more supple than older humans, so it’s good practice to teach teenagers to work their joints through a full range of motion. They’ll be grateful when they turn 50.
So what range of motion should they avoid? Compressive loads - especially on the spine - should be carefully considered.
The deadlift is a good example. A standard barbell increases the load on the lower back, because the knees are in the way of the bar, requiring the hands to move forward. A hex (or trap) bar allows the hands to stay by the side of the body and the hips to bear much more of the weight.
Proper principles like this don’t only prevent injury, but prepare young athletes for a much safer gym experience - not to mention a huge improvement in performance.
Consider why a teenager might want to get involved in gym training. For improved performance in a chosen sport, great. If resistance training IS their chosen sport, also great. But if they’re chasing some filtered physique they see on older, more muscular males (or females) on Instagram - this should be discouraged.
We all know that teenagers are susceptible to mood swings. Their mental health is more important at this age than their physical abilities, quite frankly. But with proper care and attention, positive reinforcement, and encouraging a healthy relationship with food - and themselves - gym training can be extremely beneficial for children, teenages and young adults.