Tweens and sport, part 2: what helps youth athletes through puberty

This is part 2 of a two-part series. If you haven't read it yet, start with part 1: what nobody tells you about the tween years that change so much.

Recap: What happens to youth athletes during puberty 

Puberty usually happens between about nine and thirteen for girls, and eleven and fifteen for boys. In Part 1, I explained in detail what happens with a young athlete’s body. Here is the summary.

At peak growth, young athletes can grow 7 to 10 centimetres in a year. Bones grow faster than tendons and ligaments can adapt, and legs grow before the trunk, which throws off balance and coordination. Many young athletes go through a clumsy phase. Appetite and energy needs rise sharply.

For girls, performance often stalls or dips for a while. Limbs get longer, and hips get wider, and most muscles, especially around the hip, don’t keep up, which makes girls prone to knee and ankle injuries. Body fat also increases. This weight gain is healthy and necessary, and it is part of what leads to a first period. The problem is when adults blame a girl's weight gain for her performance dip instead of preparing her (and providing the right type of training) during this time.

For boys, puberty arrives two to three years later. They gain strength and speed, but control takes time to catch up. The years just before, during and after the growth spurt, roughly eleven to fourteen, are when overuse injuries at the hip, knee and lower leg are most common. And two boys of the same age can be up to three years apart biologically.

All of this is normal. The trouble starts when adults pressure them to specialise in one sport too early, praise disordered-eating patterns, or comment on their bodies.

Not eating enough plays a big part. When food doesn’t cover the demands of growth and training, the body goes into something like a “low power mode”. This is called Relative Energy Deficiency in Sport, or REDs, and it affects bone development, hormones, mood, concentration and injury risk.

Puberty is often when young athletes get injured, start struggling with food, or quietly leave sport.

So what should we do instead?

Here is the short version.

Performance wobbles are temporary and expected. Weight gain is necessary. The injury risk is real, but it can be managed. The answer to all of it is better fuelling, smarter training, open communication, and thoughtful systems. The rest of this post looks at what each of those means in practice.

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A note on language: For the purpose of this article, "male/boy" and "female/girl" refer to biological sex and the physiological pathways associated with testosterone and oestrogen. I recognise that biological sex and gender identity do not always align, and that transgender, non-binary, and intersex adolescents navigate these changes with unique needs.

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1. Start thinking about this before puberty hits. 

As girls’ limbs lengthen and their hips widen, the muscles around the hip often don’t keep up. Many girls start relying heavily on their quadriceps instead, which changes how they jump, land and change direction, and puts extra stress on the knees and ankles.

Starting dedicated physical preparation around age ten to eleven prevents these compensatory movement patterns from taking hold and builds the resilience, structural integrity, and bone health needed during the growth spurt. It also builds confidence. A girl who feels strong and capable in her movement before puberty is far better equipped to navigate the disruption that follows. For boys, the equivalent window is around age eleven to twelve.

2. Prioritise strength training and movement pattern development over early specialisation in one particular sport. 

Avoid overscheduling or dedicating all their time to one sport (called early specialisation). Competing in one sport year-round, alongside rising training loads, significantly increases the risk of overuse injury, particularly between the ages of eleven and fourteen.

But some training changes can help. Many children, even highly trained ones, have gaps in fundamental movement skills like running, jumping, landing, throwing and balancing. I have seen firsthand how many of the most talented youth athletes can't do a simple squat or single-leg step down.

Research supports prioritising age-appropriate strength training, fundamental movement skills, balance, coordination, and neuromuscular training before and during puberty. This training should be overseen by a qualified trainer or coach who understands adolescent development, and it does not mean leaving kids unsupervised in a gym with weights.

This video shows some of the fundamental movement skills important for youth athletes. There are many different approaches, and some of these exercises might already be part of your child's sports or physical education lessons at school. It is always best to speak to a professional about your child's specific needs and goals.

3. Build structural integrity. 

Bones, joints, and connective tissue need to grow and adapt in ways that are robust and resilient to the stresses of sport. This is especially important for female athletes in weight-bearing, high-impact sports.

The developmental years are a crucial window for laying down bone and building structural integrity that will affect their bodies for the rest of their lives! About 25 percent of adult bone mass is built in the two years around peak growth.

This requires

• optimal nutrition (sufficient energy, protein, calcium, vitamin D, etc.),

• appropriate physical loading,

• and sufficient rest and recovery.

4. Incorporate nutrition advice from reputable sources. 

Young athletes in puberty need substantially more energy than the nutrition messaging around them suggests. Appetite often rises sharply and unevenly during growth spurts. That is the body asking for what it needs. For girls, the four years after a first period are especially vulnerable, as bone is still being built and hormones are still settling.

Better nutrition means consistent, well-timed meals and snacks that match training demands. Quality and timing matter as much as quantity. In Singapore, that often means planning ahead, having support from caregivers, and relying on packaged food.

Always remember that food is not only about performance. Teaching young athletes that food brings pleasure, connection, and comfort as well as fuel is not a distraction from sports nutrition. It is the foundation of a healthy relationship with eating that will outlast any sporting career.

Of course, nutrition conversations with young athletes have a place (I have built a career on it), but they need to be led by someone who understands adolescent development and the very real risk of eating disorders in this population. Without that understanding, even well-meaning conversation can do serious harm.

If you are worried about a young athlete’s relationship with food or their body, please reach out to an accredited dietitian or mental health professional with experience in eating disorders. Early intervention makes a real difference.

5. Better language from coaches makes a difference. 

When talking about food, we want coaches to talk about food in performance terms: fuel for intensity before training, fuel for adaptation after, fuel for growth on rest days, instead of moralising food as "clean", "junk", "good", or "bad". Also acknowledge (as mentioned above) that food is for fun, enjoyment, and celebration.

Avoid commenting on body weight or composition entirely. Counter body-focused talk when it arises among athletes. Make space to normalise pubertal changes where appropriate; for example, make emergency menstrual products available at training and competition for female athletes. Athletes need to understand what is happening to their bodies and have a safe space to process what comes with it.

6. Parents hold the line at home and manage the total load. 

When your child returns home, the environment you create matters enormously. Nourishing foods should be easy to access, available, and free of moral labels like "good" and "bad". Bodies should be respected without commentary. And puberty should be talked about openly, not treated as something to fear, delay or minimise.

As a parent or caregiver, you also carry something no single coach has: the full picture of your child's life and development. How many sports. How many sessions. How much sleep. How much food. Where they are in their development. Without that oversight, weekly training load can quietly become excessive, particularly during the most vulnerable growth windows.

More training is not always the answer. Sometimes the most powerful thing a parent can do is protect their child's rest. I often encourage parents to talk with their child's coach and explain their entire training schedule. Almost always, a coach will be understanding and let you know which trainings are essential and which are nice-to-haves.

Know the red flags too. Starting a period is a sign your young athlete is healthy. No period by age 15, or no breast development by age 13, needs medical attention, not a wait-and-see approach.

7. Psychological safety is not optional. 

Young athletes who feel supported rather than scrutinised are more likely to stay, communicate openly, and seek help when something feels wrong. That safety is built through coaching culture, team norms, and the consistent absence of appearance-focused commentary.

In part 1, I wrote about how sporting environments often amplify body consciousness during puberty through sarcasm, teasing, dismissive "banter", and comparisons with teammates. Adults often see these as harmless, or even as a way of toughening kids up. For a young athlete whose body is changing faster than their confidence, these comments rarely land that way.

Comparison is especially unfair in these years. Speed, strength and size depend so much on when puberty arrives that two athletes of the same age can be years apart physically. Comparing them tells a late developer they are falling behind, or tells an early developer their body is the problem.

In practice, psychological safety means giving feedback on effort, skill and decision-making, not on bodies. It means stepping in when teasing or "banter" targets someone's body, rather than letting it slide. And it means making it easy for an athlete to raise pain, periods, or worries about food without fearing they will be judged or dropped from the team.

A note to sporting bodies: kit matters more than you think

Sporting kit is one of the most visible signals a young athlete receives about whether they belong. And right now, too many are receiving the wrong signal.

There has been progress. But progress is not the same as good enough. Sporting bodies should think about kit long before an athlete reaches adolescence, because by the time they are self-conscious about their body, damage from ill-fitting, revealing, or impractical kit is already underway.

Here is what I recommend sporting bodies consider:

Size inclusivity. Kit should fit the full range of body shapes and sizes on any team. A young athlete who cannot find a kit that fits is being told, without words, that sport is not for them.

Colour. White and light colours should never be the default for kit worn during physical activity, especially for bottoms. A girl worried about her period showing through her kit isn't focused on performing. And of course, the people washing the clothes will thank you.

Secure pockets. Secure, functional pockets for sanitary products should be standard. Why? Because at some point all females will need to play a match or attend a practice while on their period. And during breaks, she can go to the bathroom to change her menstrual product. Without a pocket, she has to go to her kit bag, hide the product in her hand, then go to the bathroom. That makes something simple much harder.

Offer more than one option. Not all athletes have the same bodies, cultural backgrounds, or religious beliefs. Not all 14-year-olds want to wear the same style of tight shorts or a form-fitting dress. For adolescent athletes, policies should always include more than one option and provide some flexibility. Offering different styles of shorts (biker shorts vs regular shorts). Instead of a tight-fitting dress, offer a tank top or T-shirt with the option of a skirt, skort, or shorts.

Involve the athletes. Athletes should have a voice in kit decisions. I have found adolescents incredibly resourceful about what they want and need. A club that consults its young athletes is sending a clear message: your comfort matters here. You belong here.

Check out Inclusive Sportswear's Fix the Kit Campaign for more information and research on creating an inclusive PE or sporting kit.

The goal is simple. A young athlete should arrive at training and competition focused on their sport, not worried about how they look. This is especially important for females in sport, where, for too long, the focus has been on how they look instead of what they can do.

What I want you to take from this

Early adolescence is one of the most physically disruptive periods of a young athlete's life. The body is doing something remarkable: building bone, developing hormones, reorganising movement, preparing for adulthood. That is a good thing. But it is also the period when sporting environments most often respond with pressure, overtraining, food restriction, and body commentary instead of support.

That gap between what young athletes need and what they typically receive is where athletes often get sick, injured, or leave sport altogether.

It does not have to go that way.

We have learned in sports psychology that how athletes talk to themselves, how connected they are to their bodies, and whether they have an identity beyond sport all shape both performance and wellbeing.

If you are a coach: your words about food and bodies carry more weight than you may realise. You can explain what is happening, normalise the change, and keep a young athlete in their sport. That is not a small thing.

If you are a parent: your child's changing body may trigger memories of your own experience growing up, your own relationship with food, with sport, with how your body was talked about, and what you wished someone had done for you at that age. That is worth noticing. Because how you respond to their puberty will shape how they experience it.

You do not need to have all the answers. You just need to be on their side.

If you would like support navigating this, for your child or for your team, I would love to hear from you.

References

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• Sundgot-Borgen, C., Sundgot-Borgen, J., & Mathisen, T.F. (2026). Appearance pressure, body image, and nutrition practices in youth athletes: Implications for performance. International Journal of Sports Physiology and Performance. https://doi.org/10.1123/ijspp.2025-0687

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