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  • Writer's pictureChristie Robson

Puberty, Performance & Potential

Puberty, the natural transition from childhood to adolescence, is a pivotal stage in a young athlete's life. While it's often associated with physical and emotional changes (which often are focused on negatively), it also plays a significant role in improving athletic performance - both in the short term, and for life! 

It’s no lie it can be a challenging at the time for young athletes and adolescents; but if we can support athletes to embrace it, change training and sport to suit them, and fuel appropriately, they are going to stay happy, healthy and be in sport for the rest of their lives! 

If puberty is delayed or it’s full potential isn’t reached, then teens simply won’t reach their potential in sport and life. Plus, it can have impacts on their general health and wellbeing. 

When I work with junior athletes, we always focus on fuelling the person first, then the athlete. Why? Because they have high energy needs for growth and development, which need to be optimised first before we can optimise their sporting performance. And, if we can optimise their growth and development, they’re going to be at a lower risk of low energy availability and ultimately REDS (relative energy deficit in sport).

LEA and REDS occurs because there is a mismatch between energy in and energy out… plus typically the body is being overworked, and not getting rest and time to adapt to training. Too often I see young athletes doing way too much training each week in a rush to be the best or get to where their idols are at (who are usually 5-10 years older!). We all know the saying quality over quantity, and it couldn't be more true for adolescent athletes!

LEA can delay or impact puberty, along with impacting overall health and performance. Key points to look out for: 

  • Irregular or loss of menstrual cycles; or no cycle before 15-16 yrs of age for females

  • Less than 5 morning erections for boys

  • Impaired growth and development

  • Low blood testosterone, oestrogen or other hormones

  • Irritability, low mood, low motivation for training

  • Injuries, sickness, prolonged rehab

  • Stress fractures and bone breaks 

  • Going on ‘diets’ or restricting food groups when no allergies or intolerances

  • Fatigued constantly (and not just from training)

  • Gut discomfort or digestive changes

  • No appetite OR always feeling hungry

  • Unintentional weight loss

If you or your athletes are experiencing this, reach out to your healthcare provider or sports dietitian. 

Figures: Relative Energy Deficit in Sport Conceptual models for Health and Performance. Mountjoy M, Ackerman KE, Bailey DM, et al. Br J Sports Med 2023;57:1073–1097.

Now, let’s dive into what junior athletes need to be eating; and ways they can support puberty, their mental health, performance; and the performance benefits that come with puberty and development. 


  • Oestrogen and testosterone rise = helps build strong bones and support overall health 

  • Increased strength and power

  • Reduced injury and illness risk 

  • Improved performance long term = it’s completely normal for sporting performance to drop or plateau during puberty as hormones are changing, bodies are changing, and athletes need to grow into this and adapt. BUT, if you allow puberty to do its thing (ie. allow hormones to rise), then performance long term will reach its potential 

  • We go more into detail at the end on more hormones


Puberty is a period of accelerated growth, hormonal fluctuations, and enhanced athletic potential. To harness the full benefits of this phase, it's essential to address the unique nutritional requirements of adolescent athletes.

  • Energy Intake: Adolescents experience a surge in energy expenditure due to growth and increased physical activity. They’re not just hungry all the time to annoy parents!! So making sure they eat enough food to support their growth and athletic demands is essential!

  • Macronutrients: Carbohydrates, proteins, and healthy fats play vital roles. Carbohydrates are the primary energy source, especially for young athletes engaged in high-intensity sports. Proteins aid muscle growth and repair, and fats support hormonal balance and overall health.

  • Hydration: Proper hydration is critical for young athletes, as they may not always recognise their thirst. Staying well-hydrated with water supports performance and helps prevent heat-related issues. Only use sports drinks if it helps meet their carbohydrate needs or as they mature and develop into young adults. 

  • Calcium: Adolescents need adequate calcium for optimal bone development. Dairy milks, yoghurt, cheerse, custard, fortified soy milk and other plant milks, leafy greens, and supplements (if necessary) can help meet this requirement.

  • Iron: Many adolescent athletes, particularly females, may require extra iron to compensate for losses during growth spurts and menstruation. Go for Iron-rich foods such as eggs, lean meats, beans, and nuts, seeds and fortified cereals.

  • Vitamins and Minerals: A variety of fruits and vegetables provide essential vitamins and minerals. Vitamin D is essential for bone health, while iron, zinc, and magnesium are important for overall performance. Add flavours and sauces to veggies if this helps kids eat them - we want food to be tasty!!

  • Protein Quality: Encourage lean protein sources like poultry, fish, beans, and legumes. Athletes may need slightly more protein to support muscle growth.

  • Carbohydrates: Complex carbohydrates from whole grains, fruits, and vegetables are vital for sustained energy. They replenish glycogen stores after exercise and enhance endurance.


  • Smart Snacking: Adolescents often have busy schedules. Teach them to choose nutrient-dense snacks like yoghurt, nuts, and whole-grain crackers to support energy levels.

  • Balanced Meals: Encourage balanced, nutrient-rich meals that include all food groups. Use the plate model when plating up meals or choosing meals out as this will help athletes get the essential nutrients they need for growth and performance.

  • Timing: Proper meal timing is crucial. Eat a balanced meal or snack 1-3 hours before exercise can improve energy levels. After exercise, eat a meal or snack within 1 hour for optimal recovery.

  • Pack two lunch boxes! If athletes are going to school and then training afterwards, or before and after school, get them to pack a lunchbox for school with all the food they need, and a second one for after school filled with foods to fuel their afternoon training. Most junior athletes I talk to typically eat all their food by lunch time and have nothing for training…which means they can go 6 to 7 hours without eating!! 

  • Don’t compare to others: limit talk with your athletes around body weight, body image, avoid commenting on others food and body image. Body composition doesn’t equal certain performance. It’s essential that athletes are supported to fuel well, eat regularly, and eat a wide variety of foods. Limit the use of “good foods” and “bad foods”.


Here are some of my favourite ways to fuel around training: 


  • Muesli bars, nut bars

  • Up and Gos/ milk poppers

  • Yoghurt +/- muesli / granola

  • Fruit (fresh, frozen, tinned/canned) 

  • Cheese and crackers

  • Peanut butter sandwiches

  • Tuna or hummus and crackers

  • Biscuits/ cookies, muffins

  • Energy balls 

  • Roasted chickpeas, popcorn, mini potato chip packs

  • Dried fruit 

  • Smoothies

  • Cereal 

PRE-TRAINING = carbohydrates for energy

  • Bread/ toast with spread

  • Cereal with milk or yoghurt

  • Fruit juice/ fruit

  • Muesli bar/s 

  • Up and Go / chocolate milk 

POST TRAINING = protein to repair + carbohydrates to refuel

  • Up and Go / chocolate milk 

  • Sandwich or wrap with meat and salad 

  • Yoghurt and muesli / granola

  • Smoothie with milk and fruit 

  • Eggs on toast/ wrap 

  • Nut bar and fruit

  • English muffin with egg/s and cheese

If you'd like to learn more about how you can optimise your health and performance, let's have a chat! Click here for a 15 minute complimentary call


  • Testosterone and Growth Hormone: During puberty, both males and females experience an increase in testosterone and growth hormone. These hormones are responsible for muscle development and strength. In males, testosterone plays a significant role in building lean muscle mass, while in females, it supports muscle growth and overall athletic performance. An optimal balance of these hormones is essential for gaining strength and power.

  • Oestrogen and Bone Health: In females, oestrogen levels rise significantly during puberty. Oestrogen plays a crucial role in maintaining bone density. Adequate bone density is vital to withstand the physical demands of sports and reduce the risk of stress fractures and injuries. Ensuring that young athletes have proper nutrition, including calcium and vitamin D, can help support healthy bone development.

  • Insulin-Like Growth Factor-1 (IGF-1): IGF-1 is produced in response to growth hormone and plays a significant role in muscle and bone development. It promotes the growth and repair of tissues, which is particularly important for adolescent athletes to recover from training and competitions.

  • Cortisol: While cortisol is typically associated with stress, it is also essential for maintaining blood pressure and providing energy. However, excessive or prolonged exposure to cortisol due to overtraining and inadequate recovery can negatively impact health and hinder performance. Proper nutrition, rest, and stress management are crucial in balancing cortisol levels.

  • Thyroid Hormones: Thyroid hormones influence metabolism and energy production. Athletes need a well-functioning thyroid to maintain energy levels and support overall performance. Proper nutrition, including sufficient iodine, is necessary to support thyroid function.

  • Adrenaline and Norepinephrine: These hormones are responsible for the "fight or flight" response and play a role in alertness, focus, and reaction time. While these hormones can enhance performance by increasing alertness, excessive stress and anxiety can have a negative impact. Stress management and mental training are important for young athletes to harness the benefits of these hormones without being overwhelmed by stress.

  • Melatonin: Melatonin regulates sleep-wake cycles. Quality sleep is essential for recovery, growth, and overall health. Ensuring young athletes have consistent sleep patterns and get enough sleep and rest (8-10 hours sleep per night) is vital to support their training and performance.

  • Serotonin and Dopamine: These hormones influence mood, motivation, and emotional well-being. They play a role in the psychological aspect of sports performance. Adolescents experiencing hormonal changes may also have mood swings and emotional fluctuations. It's important to provide emotional support and teach athletes how to manage their emotions effectively.

I hope this has sparked some ideas for your own fuelling or for your junior atheletes. Remember, it's okay to take your time. Rest and adaptation is key... it's where the magic happens. And, as I always say, nutrition is individual. Just like you don't have the same shoes as your friends, or the same bike set up, your food needs to be different too!

Happy training and eating,



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