IF YOU WANT to really rile up some parents, just ask them when they think a kid is old enough to safely start strength training.

Talk to someone vehemently against putting “dumbbells” and “children” in the same sentence, and their argument against youth training likely centers around one of two things: the idea that lifting weights can damage kids’ growth plates, thereby stunting their growth, and/or that weight training can increase their kids’ risk of a bone fracture.

Sounds scary, right? But here’s the thing: Both arguments are completely unfounded. There’s no truth to either of them.

“I have no idea where these myths started, but the evidence is clear: It is absolutely safe for kids to start lifting weights early in life, provided they do so under a well-designed, supervised program,” says Gregory Myer, Ph.D., director of research and The Human Performance Laboratory for the Division of Sports Medicine at Cincinnati Children’s Hospital Medical Center.

Myer and Avery Faigenbaum, Ed.D., C.S.C.S., professor of health and exercise science at the College of New Jersey, are two of the foremost researchers in the field of adolescent fitness and strength training. Both say there is almost zero downside to strength training for children, as long as they’re doing a sound program and under proper instruction. What’s more, both argue teaching our kids to squat and press early in life is one of the best things we can do for them.

Here’s our deep dive on the science of weight training for kids and adolescents.

For starters, let’s define “lifting weights”

For the record: We’re not exactly talking about a 7-year-old pressing a 200-lb barbell above her head. In essence, we’re talking about training kids like adult athletes, with the goal of simply getting strongerpreventing injuries, and facilitating performance both on and off the field.

“Strength training broadly defines the method of conditioning that makes muscles stronger,” Faigenbaum explains. “One extreme is a bodybuilder mentality, where the goal is focused on aesthetics—that’s an adult goal. We’re talking about the other end of the spectrum, which is building completely functional strength.”

So no, little Sally won’t look like a bodybuilder—but she will be stronger than the other girls on her soccer team.

Resistance training can improve a young athlete’s potential by preparing him to learn complex movements, master sports tactics, and step up to the demands of training and competition, according to a 2016 study analysis published in the British Journal of Sports Medicine. Furthermore, strength training actually reduces the chances of a kid getting injured playing a sport, according to a meta-analysis in Current Sports Medicine Reports. In fact, mere sports training isn’t enough for kids to make the neuromuscular gains they need to prevent injury and promote lifelong health, that same analysis found. Kids actually need additional activity.

Also: Stop imagining Billy pumping iron a la vintage Schwarzenegger. “Just as with an adult, kids work at bodyweight until they can perfect their form,” Faigenbaum says. “Once a child can perform the basic movement of a bench, squat, or lift correctly, he earns the right to progress to adding weights to it. We certainly have teens in our programs who can squat double their bodyweight, but they’ve built up to that weight over time.”

And for helicopter parents concerned about their kids handling added weight, consider this: When kids run and jump and play, they land and hit the ground with an impulse load of 2–10 times their bodyweight going through their bones and joints, Myer says. That means a healthy 10-year-old boy can be looking at some 1,000lbs on his joints—which is way more than anyone’s suggesting he squat. Without learning the proper way to jump and land—and without building a strong foundation to absorb that impact—that 10-year-old boy is at a much higher risk of injury absorbing that impact without any training under his belt. In fact, resistance training can protect against injury and help nonathletic kids develop “physical literacy” to offset their sedentary lifestyles, according to a 2017 study published in Sports Health.

So how young is too young?

Most kids are ready to start intentionally building strength by 7 or 8 years old, both experts agree. The only real concern? Whether a child is emotionally ready for training. “Kids have to be able to follow instructions to stay safe, so when they have the maturity to listen and follow instructions, they’re ready for some sort of strength program,” Faigenbaum says.

Obviously some kids aren’t quite ready at age 8, but Faigenbaum’s team does strength programs with kids as young as kindergarten. At that age, strength training looks like frog squats, bunny hops, hermit crab touches, and bear crawls across the yard or gymnasium—moves that are fun and solely intended to get kids moving in all different directions, starting to build up muscle naturally.

Another gauge: If your tyke is ready for sports, he’s certainly ready for strength training, Faigenbaum adds. If your kid is already past 8, get him or her in now. Here’s why.