Every case of RED-S is complex and unique, yet there are a number of signs and symptoms to look out for. The RED-S CAT™ Clinical Assessment Tool (CAT) can be a useful resource for exploring these further, ideally with a medical professional.

Physical signs

  • Unexplained fatigue/low energy

  • Recurrent or persistent injuries (including bone and soft tissue injuries)

  • Recurrent or persistent illness

  • Decreased training adaptation

  • Stagnation or decline in performance

Strategies to identify and monitor symptoms

  • Note down anything you’ve been experiencing: illnesses, injuries, niggles, inconsistencies in training, fatigue, changes in mood, difficulty adapting to training or generally poor performances

  • Consider keeping a training diary that includes your daily training, energy levels, mood, and sleep quality

  • Consider discussing your nutrition and exercise habits with a registered dietitian to assess whether your intake is sufficient relative to your body's needs

  • If you've experienced a bone-related injury (or multiple) and haven’t already had a DEXA scan, try to do so via your GP or sports doctor (head here for guidance)

Physical signs

  • Secondary amenorrhea - missing or irregular periods when a regular cycle had previously been present

Strategies to identify and monitor symptoms

  • Consider whether you’ve missed any periods or showed subtle signs of menstrual disturbance, such as a longer length of time between periods. Tracking your cycle and symptoms via an app like FitrWoman can be really helpful. Be aware that a withdrawal bleed from hormonal contraceptives, such as the oral contraceptive pill is not the same as a natural period.

Physical signs

  • Primary amenorrhea in females – menstrual cycle has not begun by the age of 15

Strategies to identify and monitor symptoms

  • If you're over 15 years old and haven't had your first period, it is essential to see a doctor who can investigate possible causes, including RED-S

Physical signs

  • Low libido (in males and females)

Strategies to identify and monitor symptoms

  • Keep tabs on your sex drive (if you're of the age to have one) to check for signs of hormonal disruption. Make a note on whether it’s been lower than usual or absent completely. For males, experiencing fewer than 3 morning erections per week is a sign that your endocrine system is lacking the energy for 'non-essential' functions.

Physical signs

  • Iron deficiency

Strategies to identify and monitor symptoms

  • Ask your medical practitioner to check your ferritin levels and ask to view the result - note that the optimal range for athletes differs from the ‘normal range’ identified in the lab. More advice on this here.

Physical signs

  • Scoring low on an energy availability scale

Strategies to identify and monitor symptoms

  • Head here for more details

Psychological signs

  • Increased irritability, poor concentration, depression

  • Unwillingness to take rest days, including continuing to train when in pain or unusually fatigued

  • Anxiety around meal times or avoidance of eating certain food groups such as carbohydrates or fats

  • An irrational fear of weight gain

  • Feeling the need to ‘earn' food

  • Body dissatisfaction: negative thoughts about one's body or an untrue belief that changing its size/shape will result in performing better or feeling happier

  • Body dysmorphia: believing that one's body does not fit the ideal for your sport

Try to answer these questions as accurately and honestly as possible

  • How do you feel about your weight and body?

  • Are you trying to lose or gain weight?

  • Do you believe that losing weight could improve your performance?

  • Are there certain foods you try to avoid or eliminate from your diet?

  • Do you feel a need to exercise to ‘earn’ food, or to eat less on rest days than you would on training days?

  • Do you try to avoid rest days from training or feel an urge to make them ‘active’ rest days?

  • What percentage of the time do you spend thinking about food?

  • Do you find it hard to sit down and truly rest?

  • Do you find yourself sticking rigidly to exercise plans, even if it means ignoring your body's signals, like fatigue or pain?

  • Do you think you might have an eating disorder?

  • Would some of your eating behaviours be considered disordered?