There are many myths about strength training. Among them is the myth that weightlifting stunts growth. It’s simply not true. There are, however, other reasons why you might want your kids to strength train with variable resistance versus free weights. We explain.
Does Weight Lifting Stunt Growth?
There’s a myth that weightlifting stunts growth and that kids who strength train at too young of age won’t meet expected milestones in terms of height. This myth couldn’t be further from the truth.1
Naysayers say heavy loading can damage growth plates, which may have a negative effect on height. Growth plates are an area of special tissue near the end of bones. This tissue is where bone elongation occurs. Growth plates are vulnerable to injury because they are weaker than the surrounding bone. The most common injuries to growth plates are the result of blunt force trauma. When treated properly, most growth plate fractures heal without lasting negative effects.2
In a rat study, researchers demonstrated that heavy loads can stifle growth. However, this dose-dependent effect was achieved at extreme, forced loads. What’s more, the bones of the rats returned to normal after a one-week rest period.3
Few studies have followed the long term effects of early-age resistance training on human growth. Those that have demonstrated no link between weight training at a young age and reduced linear growth.4
Strength training in kids increases the growth factor in the bloodstream.5 And instead of damaging bone, resistance training at a young age can build bone strength, potentially protecting against osteoporosis as kids get older.6 In a study of 6th grade girls, those participating in strength training showed markers of improved skeletal growth.7
Researchers, however, are careful to point out that none of this means heavy loading with free weights is risk-free for kids. Strength training is safe for kids when the loads are not excessive when kids can control their form, and when the risk of blunt trauma (from dropping weights) is managed.
Why Strength Training is Good for Kids
Strength training benefits kids by improving physical literacy and neuromuscular coordination and by preventing injury.8 What’s more, strength training can give kids a sense of confidence and accomplishment, can help establish life-long healthy habits, and can (and should) be fun.
Parents who wish to introduce their kids to resistance training can keep it safe by better understanding the benefits, and limits, of strength training for kids.
Hypertrophy in Kids
Before puberty, kids just don’t have the hormones to build muscle the same way adults do. Extreme hypertrophy in kids is generally the result of a genetic anomaly and not due to intense weight training.9 So, increasing muscle size (versus just getting stronger) should never be a reason for a child to lift weights.
When kids realize strength gains from resistance training, it has far more to do with improving motor neuron recruitment than increased muscle fiber size.10 However, this is a great benefit when it comes to general health, functional fitness and improved sports performance.
As noted above, involving kids in strength training programs helps train a better brain-body connection. Better coordinated, stronger kids are less likely to get injured. This is even true for kids who are highly trained in another sport. General resistance training can help balance the body making overuse injuries less likely.
Health and Wellness
Strength training can be a fun way to introduce kids to the habits that will keep them healthy life-long. Strong kids are also more likely to be insulin sensitive, which significantly lowers metabolic risk.[^11],11 The benefits of strength training are just physical either. Kids who are physically strong have a greater sense of self, are less likely to be anxious, and are more resilient to mental stress.12
Why Variable Resistance Training (VRT) is Best for Kids
Variable resistance training (VRT) is more effective and safer for kids for the same reasons why it’s smarter and safer for adults.
A Dynamic Strength Curve
VRT follows the natural strength curve of the body. This means that the load seems lighter at the bottom of a lift, when the body is in its most compromised, unsafe position. As the lift progresses and the body opens into a safer, stronger, impact-ready position, the load increases.
This more natural, dynamic strength curve keeps kids safer by limiting the load on their growth plates when the body is in a weak position. It also helps kids get stronger by challenging them the most in the postures where they are the most stable.
For kids, building strength is less about building muscle and more about building neurological pathways. Resistance training with bands thus maximizes this potential, as it’s naturally more neurologically challenging than working with weights.
Because VRT requires core stabilization, it recruits more muscle fibers. Each exercise engages the whole body, and trains much more than just one isolated area. For adults, this leads to greater muscle growth. For kids, this type of engagement builds strength by building more efficient neural pathways.
Variable Resistance for Kids
Beyond the evidence-based benefits, variable resistance training with the X3 bar is just plain fun for kids. Whether or not it’s a fit for your child will depend on height and body shape more than age. As long as your child is mature enough to maintain correct form and follow safety protocols, VRT will offer them everything weight training does, and more.
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