Is It Safe For My Tween To Work Out?

When my son started high school (in 7th grade because we’re in Quebec), he had access to a fully-equipped gym, and he spent his lunch breaks with friends working out. While gym teachers were nearby, I knew his daily exercise didn't follow much of a routine or plan—and he didn't have much supervision.

On social media, trends like “gymmaxxing” and “looksmaxxing” can make working out feel less like healthy movement and more like a race to get bigger, leaner or more conventionally attractive, sometimes before teens understand how to train safely.

It made me wonder: Is it safe for tweens to work out, especially considering they're still growing and developing?

Luckily, my brother is a personal trainer and was able to weigh in on things (pun intended), as well as provide my son with pointers on a workout plan, diet and more. But not everyone has a fitness expert in the family, and tweens should take precautions when regularly exercising in a gym setting. Here's what we learned.

Know your surroundings

Tweens need to understand the safest way to use gym machines. Even a treadmill can pose risks. And when kids are with friends, they may not pay the same amount of attention to safety. This is why most public gyms require kids under a certain age (usually 15 or 16) to be accompanied by an adult.

Make sure your child is aware of the dangers and let them know they can ask one of the teachers or trainers to show them the proper way to adjust weights, manipulate pulleys, and more.

Watch their weight

One concern parents often hear about is growth plates, the soft areas near the ends of children’s and teens’ bones where growth happens. Because they’re still developing, they can be more vulnerable to injury from excessive stress, poor form, or overuse. "The biggest concern with growing kids working out is the compression of growth plates," says Marc Lalonde, a certified personal trainer in Pointe-Claire, Que. But the broader issue isn’t strength training itself; it’s unsupervised lifting, using too much weight, or following a poorly structured program. With age-appropriate exercises, proper technique, and supervision, strength training is generally considered safe for kids and teens.

Instead of using too many weights, Lalonde recommends resistance training, which doesn't require weights at all. Think push-ups, lunges and crunches. “Their body weight can be a resistance without touching a weight ever."

Peer pressure can also be an issue. "It’s my experience [at] they go to the gym, they fart around," Lalonde said. He adds that teenage boys, especially, want to show off how strong they are and tend to try to lift too much weight. That pressure can be amplified by social-media trends like gymmaxxing, which often frame exercise around appearance and performance rather than safe, age-appropriate training. But workouts should be structured, with an appropriate number of reps and sets. "It’s about working out in a way that challenges them appropriately and isn’t a waste of anyone’s time."

Pay attention to diet

Diet plays an important role when tweens are working out regularly. It’s important to eat the right foods both before and after physical activity.

“You want to always be in a position where you’re achieving maximum results, and protein is a big part of that,” Lalonde said. “Protein is a substance that, once your body takes in as much as it needs, it passes the rest, whereas simple carbs, sugars, and starches will be retained as sugar in the bloodstream. You want to be very smart about refilling your protein reserves immediately post-workout when muscles are the hungriest. Getting lean protein in shake or food form takes on more importance with kids at that age.”

Age-appropriate workouts

For tweens, exercises that work well for this age group include:

• Cardio (5–10 min warm-up/cool-down): Treadmill (walking/jogging), stationary bike, rowing machine or elliptical.
• Strength and resistance: Bodyweight exercises are best to start, including squats, push-ups (knee-modified if needed), lunges and planks.
• Machine weights: If your tween insists on using the machines at the gym, pin-loaded machines (like leg press or chest press) are generally safer than free weights because they control the range of motion.

Regular activity is healthy, but structure matters

Whether a tween is inspired by sports, friends or social-media trends like looksmaxxing, the goal should be the same: helping them build healthy habits, not chase risky shortcuts. Regular physical activity is good for tweens: it supports bone and muscle health, mental well-being, sleep and long-term healthy habits. But those benefits are most likely to show up when exercise is age-appropriate, well supervised and properly structured.

That’s the key distinction. A tween who is learning good form, using manageable resistance and getting enough rest is in a very different situation from one who is lifting too heavy, copying friends or pushing through pain. The goal isn’t just to get kids moving—it’s to help them exercise in a way that is safe and sustainable.

My son loves being at the gym. It’s a positive place to spend time with other kids his age, and it keeps him active. If your tween is going to a gym, check in regularly about how they’re training, whether they understand the equipment and whether they’re dealing with pain, excessive soreness or noticeable weight loss.