How Playing Sports In Childhood Can Impact Your Body In Adulthood

Meet the experts: Lacee Lazoff, CPT, is a personal trainer, kettlebell specialist, and founder of Bells Up, a virtual kettlebell-focused strength training program. Alexander Rothstein, CSCS, ACSM-EP, is an exercise physiologist and instructor for the Exercise Science program at New York Institute of Technology.

What We Know About How Childhood Sports Influence What Your Body Looks (And Moves!) Like Later On

The specifics on how your early sports experiences impact your body down the line vary for everyone based on what sports you played as a kid, for how many years, how intense your training was, how you’ve trained since then, and even genetics. But what is abundantly clear is that childhood sports *can* affect long-term body development in more ways than one.

Muscle Memory

When people talk about “muscle memory,” they usually mean a particular physical skill or ability that comes relatively easily, without requiring much effort or conscious thought, says Alexander Rothstein, CSCS, ACSM-EP, an exercise physiologist and exercise science educator. Think about riding a bike, for example—once you’ve learned, you can go years without doing it and still pick it up quickly.

But here’s the thing: Muscles themselves don’t actually “remember” anything, Rothstein says. “It’s really your brain and nervous system remembering how to do something you have previous experience with.” So, when you participate in a sport as a kid, you’re essentially training and conditioning your nervous system for that activity. This means that years later, those neural pathways make it easier for you to pick up the same skill compared to someone without that earlier experience.

Muscle memory helps you keep coordination and motor skills for familiar activities, which can make staying fit as an adult easier if you were active as a kid, says Lacee Lazoff, CPT, a personal trainer and kettlebell specialist. “Strength, mobility, flexibility, and coordination can fade, but someone may have an easier time developing these skills due to muscle memory,” she explains. For example, if you could do the splits as a child, you may have lost that ability, but with practice, it’ll likely come back faster than for someone who’s never done it before, she says.

There’s also a science-y side to what’s happening inside the muscles. When you build muscle, your individual muscle fibers increase in size and number of nuclei (the “control centers” of muscle cells that are responsible for growth and repair), Rothstein explains. Even if you stop exercising and lose strength, those extra nuclei building blocks stick around, helping you regain strength more quickly when you start working out again, according to a 2020 study out of Acta Physiologica. So, if you had strong arms from playing softball as a kid, your muscles have a head start because those building blocks never fully disappear, even if your strength declines temporarily.

Bone Density

Bone density is basically how strong and solid your bones are, says Rothstein. The denser your bones, the less likely they are to break. While eating a nutritious diet helps, the real key to building strong bones is doing weight-bearing activities, like running, jumping, or lifting weights, says Lazoff.

What many people don’t realize, though, is that the most important time to build foundational bone density is before 20 years old. “The cool thing is that those who play sports through their formative childhood years usually have a larger degree of bone density throughout their lifetime,” says Rothstein. Recent research backs this, finding that the accumulation of bone density in childhood has a clear correlation to bone health later in life.

Now, this doesn’t mean you should skip weight-bearing exercises as you age, though—they’re still important to help prevent conditions like osteoporosis, per the National Library of Medicine.

Body Type

Your body type is how your weight and proportions—like muscle, fat, and bones—are distributed. While genetics play a role in determining your body’s unique composition, in general, the more muscle you have, the easier it is to keep off fat and maintain a lean build, says Rothstein. Muscle can come and go at any age, but kids who are active might have a head start in building good habits and developing muscle (thanks to muscle memory), adds Lazoff.

But back to the genetics factor for a sec. It’s important to point out that some people are naturally born with an athletic build, which can give them an advantage in playing youth sports and the perks that come with it. For example, if you’re tall and fast and play lacrosse, you might get more attention from coaches. As a result, you may be given more opportunity to train and continue the sport, ultimately promoting muscle growth, endurance, and an overall lean body shape, says Rothstein.

But the body is tremendously adaptable and can change at any age regardless of genetics.

It may be easier for some people than others, especially if they were exposed to regular exercise at any early age, but everyone’s body can change to a pretty considerable degree with the right ingredients (read: fitness and nutrition), Rothstein says.

Muscle memory may be more so a product of your early years, but bone density, muscle tone, and body shape can all be controlled and/or changed now. “If your goal is to have more muscle or less fat, it doesn’t matter what you did or looked like in your youth, as long as you make health and fitness choices today that are aligned with your goals,” he says. “Developing athletic skills as a younger person can definitely help, but it’s not a requirement by any means.”

In other words, the “born with it” mindset is a myth. “It’s never too late, and nothing is guaranteed, regardless of past results,” notes Lazoff. If you want to change your body, it boils down to a consistent exercise routine and nutrition regimen, regardless of your athletic past, she says.

How To Apply This Knowledge To Your Current Fitness Goals

It’s never too late to take control of your health and fitness, whether you played childhood sports or not, says Lazoff. “Although sports in childhood are beneficial, they are not going to make or break fitness progress as an adult.” The following tips can set you up for success:

1. Identify a goal. Before you overhaul your entire life to “get fit,” Lazoff recommends starting out with one specific, measurable goal. For example, if you want to be able to do a pushup, your goal could be: “Complete one full pushup with proper form in eight weeks,” she describes. From there, break the goal down into smaller steps, like practicing incline pushups on a bench or strengthening your chest and triceps with exercises like dumbbell chest presses and triceps dips a certain number of times per week. This approach helps to keep your focus clear and progress trackable.
2. Do your research. Once you’ve set a goal, do your homework to create a fitness and nutrition plan that supports it, says Rothstein. The more you understand why certain exercises or fitness choices are beneficial, the more motivated you’ll be to stick with them, he says. In regards to the pushup example, this might mean researching progressive overload techniques to build strength in the chest or learning how to activate your core to support proper pushup form.
3. Focus on your diet. A sound nutrition plan can help you meet your goals much sooner than exercise alone, says Rothstein. There’s no one-size-fits-all approach, but starting with a high-protein diet and adequate hydration are key to success. Cutting back on added sugar, processed snacks, and calorie-dense drinks like soda and sweetened coffee can help you stay on track.
4. Emphasize getting stronger. No matter your goal, resistance training is the golden ticket for muscle development, bone density, and weight loss, says Lazoff. Not sure where to start? Check out the Women’s Health Workout Finder Tool to lock down a routine that fits your goals, equipment preferences, and timeframe.
5. Be patient. Achieving physical fitness goals takes time, so Lazoff’s number one piece of advice is to be patient and stay consistent. “Your body will respond with a consistent training and nutrition plan, no matter where you’re at today.” And don’t forget to celebrate small wins along the way—like progressing from incline pushups—as these milestones help us stay motivated.


Andi Breitowich is a Chicago-based writer and graduate student at Northwestern Medill. She’s a mass consumer of social media and cares about women’s rights, holistic wellness, and non-stigmatizing reproductive care. As a former collegiate pole vaulter, she has a love for all things fitness and is currently obsessed with Peloton Tread workouts and hot yoga.