The Hidden Signs of RED-s When Periods Aren’t the Clue

RED-s vs The Female Athlete Triad

To start, I do want to give you a bit of background information on why the absence of menstruation has been the primary sign we look for when a woman is in a low energy availability state. The impact of low energy availability was first investigated as part of the Female Athlete Triad. The Female Athlete Triad describes how low energy availability results in reductions in ovarian activity and hormones, which could then impact our bone health. Research on this relationship between energy availability, hormones and bone health has been investigated in sport science research since the 1980s. While we have a substantial amount of research on the Female Athlete Triad, this model was expanded in 2014 when researchers and health professionals recognised that problematic low energy availability (e.g. severe or prolonged period of time in a low energy availability state) affected numerous body systems. The impact of problematic low energy availability on health and performance was the original work that was done on Relative Energy Deficiency in Sport (RED-s) syndrome.

Since the original statement on RED-s in 2014, we have seen a large amount of research completed on this topic in the last decade. With all of this new research, an updated research statement was released in 2023, and in a series of publications researchers and health practitioners provided details on a revised RED-s screening model. This new RED-s screening model was described as a traffic light system, with green representing low to no risk, yellow as mild risk, orange as moderate risk and red as very high risk of RED-s.

The RED-s Criteria 

For a person to be at high risk of RED-s (e.g. in the Red) and to be experiencing problematic low energy availability, they would need to be presenting with four primary clinical criteria or three primary and more than two secondary clinical criteria. Below are the primary and secondary clinical criteria in this new RED-s screening model (not including menstruation-related criteria) that may be helpful to women using hormonal contraception.

Primary clinical criteria for women include:

• Low total or free Triiodothyronine (T3, thyroid hormone).
• History of more than one high-risk stress fracture (femoral neck, sacrum or pelvis) or more than two low-risk stress fractures (stress fracture in any other location) within the previous two years or if you have had an absence of training due to a bony stress fracture for more than 6 months in the last two years.
• Bone mineral density Z-score of less than 1 in the lower (lumbar) spine, femoral neck and total hip or a decrease in bone mineral density Z-score from your previous test (if you have already done a test before).
• For individuals where disordered eating is a concern, an elevated score on the Eating Disorder Examination Questionnaire (more than 2.3 for women).

Secondary clinical criteria for women include:

• History of one low-risk bone stress fracture within the last two years, and the fracture caused a loss of training of less than 6 months.
• Elevated total or low-density lipoprotein (LDL) cholesterol levels
• Clinically diagnosed depression and or anxiety.

Medical Support 

If you do use hormonal contraception and if you are concerned that you are at risk of problematic low energy availability and RED-s, then I would strongly encourage you to seek medical support. With support from your doctor, you can start investigating if you have the combination of primary and secondary clinical criteria that would support a medical diagnosis of problematic low energy availability and RED-s. Not only will this medical support help you in getting the information that you need to understand if you are at high risk of RED-s, but it will also mean that you can get the treatment and support you need if you are in the red zone.