You’ve probably seen the photos. A kid with a shredded eight-pack, veins popping out of his delts, and a physique that looks like it was photoshopped onto a middle-schooler’s head. Most people see a 13 year old bodybuilder and immediately lose their minds. They start screaming about stunted growth. They argue about whether it’s "child abuse" or just elite discipline. Honestly, it’s a mess of opinions out there.
Tristyn Lee is usually the kid at the center of this storm. When he first blew up on Instagram and YouTube around 2017 and 2018, he was just 13. He wasn’t just "fit" for a kid. He was diced. We’re talking 4-5% body fat, according to some of his own videos from that era. That’s stage-ready conditioning for a pro, let alone a kid who hasn't even finished puberty.
People get weird about youth strength training. They really do.
There’s this persistent myth that lifting weights at a young age will "stunt your growth" by damaging the epiphyseal plates (the growth plates) at the ends of long bones. But if you actually look at the data from organizations like the National Strength and Conditioning Association (NSCA) or the American Academy of Pediatrics, the story is way different. They basically say that as long as the kid isn't trying to ego-lift 500 pounds with trash form, it’s actually safer than soccer or gymnastics.
But Tristyn wasn’t just doing "strength training." He was living the life of a monk.
What it actually takes to be a 13 year old bodybuilder
Being a 13 year old bodybuilder isn't just about hitting the gym. It’s the kitchen. Tristyn was famously committed to a strict ketogenic diet from a very young age. Imagine being 13 and saying no to a slice of birthday cake or a bowl of cereal because you’re tracking your macros for a photoshoot. That’s a level of psychological intensity that most adults can't maintain for a week, let alone years.
His routine was legendary. Wake up, fasted cardio, soccer training (he was a high-level prospect), then the weight room.
The volume was insane. He wasn't just doing a few pushups. He was hitting heavy squats, deadlifts, and high-intensity bodybuilding splits. This kind of dedication gets clicks. It gets millions of followers. But it also comes with a bill that eventually comes due. When you’re in a massive caloric deficit at 13, your hormones don't always know what to do.
Tristyn has been remarkably open lately about the darker side of that period. He’s admitted that being that shredded all year round wrecked his sleep and his hunger cues.
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The science of the "Stunted Growth" debate
Let's get technical for a second because the "growth plate" argument is usually where these conversations die.
$F = ma$. Force equals mass times acceleration. When a 13-year-old jumps and lands during a basketball game, the force on their joints can be several times their body weight. That’s often more stress than a controlled set of overhead presses. The real danger isn't the weight itself; it's the lack of supervision. If a 13 year old bodybuilder is supervised by a certified coach who understands load management, the risk of a growth plate fracture is incredibly low.
The real concern isn't the bones. It's the endocrine system.
Puberty is a massive hormonal surge. It’s the body’s natural steroid cycle. To maximize that, the body needs fuel. Fat, specifically. Cholesterol is a precursor to testosterone. If you’re keeping a kid at 5% body fat on a keto diet while they’re trying to grow, you might be pulling the emergency brake on their natural development.
Tristyn eventually hit a wall. He’s talked about how he felt "stuck" and how the constant dieting was making him miserable. He had to pivot. He had to start eating.
The transition from kid phenom to adult athlete
It’s weird watching someone grow up through a screen. You see the 13 year old bodybuilder turn 15, then 18, then 20. Tristyn is in his early 20s now, and his physique has shifted. He’s much bigger, sure, but he’s also moved away from that "shredded at all costs" mentality.
He had to learn the hard way that "more" isn't always "better."
He’s not the only one, though. You see kids like Kyle Landi or various "influencer" teens popping up every day on TikTok. The barrier to entry for bodybuilding has never been lower because of social media. You don't need a stage. You just need a ring light and a gym membership.
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But the "influencer" side of being a 13 year old bodybuilder adds a layer of pressure that the old-school guys didn't have. Arnold wasn't checking his likes after a set of curls. If a kid today loses their abs for a week during a bulk, they get "downvoted" by thousands of strangers. That messes with your head.
- The Diet Trap: Constant dieting at a young age can lead to disordered eating patterns later in life.
- Social Isolation: Spending 3 hours in the gym and 2 hours prepping meals doesn't leave much room for being a "normal" kid.
- Hormonal Health: Low body fat can suppress the very hormones needed for muscle growth and height.
Should your kid be lifting like a pro?
Probably not.
Look, strength training is great. Every kid should probably be doing some form of resistance work. It builds bone density. It fixes posture. It boosts confidence. But "bodybuilding"—the specific pursuit of muscle hypertrophy and extreme leanness—is a different beast entirely.
If a 13 year old bodybuilder wants to train, the focus should be on "the big three" but with moderate weights and perfect form. Squats, hinges, pushes, pulls.
I’ve seen kids in my local gym trying to max out their bench press before they even know how to retract their scapula. That’s how you end up in physical therapy by age 16. It’s not the weights; it’s the ego.
Tristyn Lee’s story is actually a success story, but it’s a cautionary one too. He survived the "shredded kid" phase and has matured into a very thoughtful, incredibly strong adult athlete. But he’s the exception. For every Tristyn, there are a hundred kids who burn out, get injured, or develop a lifelong complex about their body.
Bodybuilding is a marathon. It’s a sport of 40-year-olds.
What to do if you're a young athlete (or a parent)
If you're looking to get into the world of the 13 year old bodybuilder, or you're a parent of a kid who won't stop watching fitness influencers, here is the reality.
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First, stop worrying about being shredded. Abs on a 13-year-old are mostly a sign of being underweight, not being "jacked." You need calories to grow. You need carbohydrates for brain function and athletic performance. Don't fear the bulk.
Second, find a coach. Not a "fitspo" guy on Instagram, but someone who actually understands youth physiology.
Third, diversify. Tristyn was a soccer player first. That athleticism provided a base that pure lifting can't touch. If all you do is lift, you become a static object. You want to be an athlete who bodybuilds, not just a bodybuilder who can't run a mile.
The Verdict on the 13 year old bodybuilder phenomenon
It’s not going away. The "fitness" niche on social media is worth billions. Kids want to look like their idols.
The conversation shouldn't be about "banning" kids from the gym. That's stupid. We should be encouraging them to lift. We just need to change the goalpost. Instead of chasing a 4% body fat percentage—which is literally dangerous for a child—we should be chasing PRs in the squat or the pull-up.
Tristyn Lee is a freak of nature. His work ethic is genuinely one-in-a-million. But even he had to realize that his 13-year-old self’s approach wasn't sustainable.
If you want to start your journey, focus on the long game. Don't worry about the "shreds." Worry about the strength. The muscle will follow, and your 25-year-old self will thank you for not wrecking your metabolism before you were old enough to drive a car.
Actionable Steps for Youth Training
- Prioritize Form Over Weight: If you can't do 10 perfect reps, the weight is too heavy. No exceptions.
- Eat for Growth: Focus on whole foods. High protein, plenty of healthy fats, and enough carbs to fuel your sport. A 13 year old bodybuilder needs to eat like a growing human, not a dieting pro.
- Sleep is the Best Supplement: You don't grow in the gym; you grow in your bed. Aim for 9-10 hours. Your growth hormone peaks while you're asleep.
- Listen to Your Body: If your joints ache, stop. Pain is a signal, not a challenge.
- Limit Social Media Comparison: Your "pump" in the mirror is real. The "pump" on Instagram is filtered, angled, and lit by professional equipment. Don't chase a ghost.