The challenge of optimising energy availability for the busy adolescent athlete.

As the sports seasons change, it can be a good time for parents to take a breath and gear up for the next phase of their busy adolescent’s sporting schedule. The adolescent athlete has many challenges, they are at a time of their life where their body requires extra dietary energy for growth and skeletal development.

In many cases, they are competing in multiple sports as well as partaking in specific strength and conditioning sessions during school. Combine this with a full school day and potential travel times to and from trainings, families are faced with a very challenging ability to fuel appropriately.

It’s common at this age for athletes to under-fuel and, if only occasionally and not excessively, this shouldn’t be an issue. However, for the adolescent competing in numerous sports, or training across multiple sessions per day, under-fuelling can not only impair energy levels but also health, performance and long-term development.

For the adolescent athlete, the concept of energy availability is vitally important. Energy availability underpins how much dietary energy (calories) is left over to the body after exercise has been accounted for. The body needs a certain amount of energy available each day to function optimally for processes such as bone development, muscle function, the immune system, optimal hormonal profiles and, in females, the reproductive system. So, when dietary energy is not sufficient to accommodate energy burnt from exercise these important bodily processes can be downregulated.

Low energy availability underpins menstrual dysfunction and is associated with lower bone mineral density and a higher prevalence of stress fractures. Research is constantly evolving about impairments in performance and a reduced training response from low energy availability.

At the Axis performance nutrition clinic, we commonly see adolescent athletes struggling to maintain optimal energy availability. Obviously, disordered or restricted eating practises can play a significant role in this. However, in many situations, it is the unawareness of the training demands young athletes are undertaking that is causing an accidental mismatch in energy availability. Training sessions that require running or other modes of physical exertion, such as swimming or rowing, can expend a significant amount of energy. When these trainings exceed an hour and occur multiple times in a day, the dietary energy required significantly increases. As young athletes develop and progress, it can be easy to be accustomed to their training demands and for it not to feel as if it is tough.

Total energy (calorie) requirements can be 30-40% higher in adolescent athletes, compared to their sedentary friends at school and their parents and less active siblings. With the logistical challenges of providing enough food across the day, it’s easy to slip into a pattern of under-fuelling.

On top of this, it is clear the rest of the world are not in a low energy availability crisis; indeed most are in an energy surplus with record rates for adolescent obesity and inactivity. Due to this, most nutrition messages that young athletes can be exposed to at school is the promotion reducing excess energy from fat, sugar and refined foods. Often, parents will be going on a lifestyle journey to improve their own diet, which usually results in energy reduction. All these factors can result in a reduction in energy content of the young athlete’s diet by limiting food groups, snack options and often energy dense foods that may be useful at certain times.

Key nutrition tips to optimise energy availability in young athletes:

  • Be well prepared. Always have recovery snacks available post every session. This may look like packing a ready-made breakfast post-morning training to have at school and ensure a smaller breakfast is consumed before they leave. Overnight oats can be an easy option to mix up and leave in the fridge (lasting a few days) as an easy option to have post morning trainings. 
  • Ensure a quality afternoon snack. If the athlete is training in the afternoon and can’t make it home prior, really try to make sure there is enough snacks to get through for a post-school / pre-training snack. Packing extra sandwiches or energy dense muesli bars, fruits, nut mixes, homemade baking or creamed rice can be a good option here. If the training is demanding this snack becomes important to plan for but is often neglected. 
  • Pack a good lunch box. Often the young and hungry athlete will eat all their lunch box by morning tea, if they’ve trained in the morning this can cause fatigue at school and reduced performance in their afternoon training. Try to plan for 3-4 eating occasions when training before and after school and if they are unable to get home during this time. Be resourceful with left-overs, sandwiches, wraps, home baking etc. 
  • Think about the big training days. Often there will be 2-3 big training days in a week. If fatigue is high, liquids post-training, in the form of chocolate milks or homemade smoothies, can be a great option to start the refuelling process after training. 
  • Don’t confuse your lifestyle needs with theirs. It’s easy for parents to misunderstand their young athlete’s energy needs, especially those who are heavily committed young athletes. If you are changing the family’s lifestyle by adjusting dietary choices, you should pay close attention to ensure your child has the fuel available to train but also grow. Ideally, consult a sports dietitian when going down this path. 
  • Appetite won’t always be the best guide. We know with athletes that appetite is reduced after high intensity exercise, or when fatigue is high. It’s common to have a reduced motivation to eat. At these times, a reduction in excess fibre and grains and an increase in energy dense ingredients can be needed to ensure required energy intakes can be met. Source advice from a sports dietitian. 
  • Worried about low energy availability? Read through this information on Low Energy Availability. If you are concerned, please follow up with your GP. And, if you are interested in addressing nutrition, ask for a referral to the Performance Nutrition Clinic at Axis. 
  • Get your periodised nutrition plan to cover their training week. At Axis, we focus on providing an in-depth plan that ensures athletes are fuelling appropriately according to their energy needs over a training week. We will give a clear breakdown of these needs with timings and a large variety of menu options to easily plan their day.
By Dane Baker, Performance Dietitian on