Low energy / RED-S

Elite middle distance runner – low energy availability and symptoms of RED-S by Cara Sloss


  • Female, 22 years, 1.65m, 47kg
  • National level athlete – competing distances 1500m – 5km
  • Moved to university in the past year
  • Training load increased from 55miles – 70miles per week also started strength and conditioning twice a week. Has a supportive coach and this mileage increase was done gradually.
  • Living in a shared house, previously living at home with parents


  • Recent blood test shows low ferritin and vitamin D
  • Reports no regular medication
  • Has secondary amenorrhoea (no periods for past 9 months)
  • A recent history of a stress fracture in navicular – 3 months non-weight bearing
  • Currently starting ‘return to running’ programme has been cross-training twice daily throughout the injury
  • Having weekly physiotherapy

Dietary assessment

  • Detailed food diary analysis showed ~600kcal below estimated energy requirements for current training.
  • Carbohydrate intake <50% of the requirement
  • Protein intake 65% of the requirement
  • Key vitamin and minerals below requirements: calcium, vitamin D, vitamin C, omega 3
  • Factors influencing current eating pattern included:
  • Time – training twice daily plus university during the day
  • Cooking skills – admits parents previously did most of the cooking
  • Appetite – finds it difficult to eat straight after training due to the decrease in appetite post-high-intensity sessions.
  • Not aware of what current dietary needs were to support training – thought she was always eating regularly and having a healthy diet.
  • Had cut out milk a few months ago as she thought it was giving her stomach problems – not replaced with non-dairy alternative, therefore, decreased calcium intake

Goal setting from initial consultation:

  • Include carbohydrate with each meal with each meal
  • Add 2 extra snacks per day (often a barrier to this was forgetting, or feeling full – suitable examples given)
  • Include good quality fats ie olive oil, avocado, nuts, peanut butter to help increase overall energy intake.
  • Have carbohydrate based recovery snack within 30 minutes of finishing training
    example plan with meal/ snack ideas for the above given

Monitoring tools: weight, body composition (sum of skinfolds), menstruation

Review sessions planned at 4, 8 and 12 weeks during which her sum of skinfolds increased 8mm, she felt energy increased during training and had increased running up to 15 minutes. Her periods had still not returned at this point (this can be highly individual even after some weight restoration). She had her first period 5 months after the initial meeting.

The focus of the intervention was education around RED-S, the signs to look out for and a stepwise approach to improving energy availability and confidence in her ability to manage her own nutrition. In this case, she had fallen into a pattern of low energy availability inadvertently following a change in environment and training group. Her training load increased but she didn’t recognise that her fuelling hadn’t increased to compensate. A lot of encouragement was given to ensure she notices the warning signs of low energy availability and to talk with others in the training group about the importance of fuelling well.

Cara Sloss works closely with you, the countries top sports medicine doctors and our physios to resolve these issues as comprehensively as possible. Click here for more information.