Unfortunately, most nutrition information these days seems to be focusing on ways to decrease energy intake. This along with the rampant amount of nutrition misinformation is putting athletes at risk of RED-S. If you follow the running scene then you’ve most likely recently heard about “RED-S.” A lot of this is due to Mary Cain opening up about her story, and struggle with RED-S under the abuse of her coach (click here if you missed that video). This has in turn has helped to increase the awareness of RED-S. If you’ve been reading my blogs then you know that after years of working as a Registered Dietitian, I returned to school to complete a Master’s thesis in this area. I’m extremely passionate about this topic and I’ve created this blog series to provide information and further increase awareness of RED-S. This blog is the first of the series and will outline what exactly “RED-S” is.

First, let’s start with how you pronounce RED-S. There are two options. One way of pronouncing it is as one word- “redz.” Others pronounce it as two words. By saying first the colour “red” and then “s.” RED-S stands for Relative Energy Deficiency in Sport. It was first introduced in 2014 to replace the Female Athlete Triad (more on that next week). The syndrome of RED-S refers to “impaired physiological function including, but not limited to, metabolic rate, menstrual function, bone health, immunity, protein synthesis, cardiovascular health caused by relative energy deficiency.” The figures below show the health and performance consequences of RED-S. This can occur in both male and female athletes.

The underlying cause of RED-S is low energy availability. Energy availability refers to the amount of calories leftover for the body after the calories required for exercise have been accounted for. For instance, if you consumed 2000 calories, and expended 500 calories then 1500 calories are leftover for the body. If there are not enough calories remaining for the body, this is called low energy availability. This can result in the negative health and performance outcomes shown above. Mary Cain talks about some of the negative outcomes that resulted for her that included missing periods, bone fractures, and reduced performance. This is because when too few calories are available for the body, it will shut down things that are not vital for survival such as being able to get pregnant, resulting in a loss of period or putting energy into building healthy bones, resulting in compromised bone health and increased risk of injury.

It is very important to note that an athlete’s body weight or changes in body weight are not a good indicator of energy availability. Someone can have a stable weight but be in low energy availability. This is because the body can reduce its metabolism to conserve energy when too few calories are consumed. This results in a stable weight despite being in a calorie deficit (fewer calories consumed then calories burned). Athletes can also be at a “healthy” weight or even “overweight” and still have low energy availability. You can not tell by looking at someone if they have RED-S.

As I mentioned above, RED-S was introduced to replace the female athlete triad. Next week, I’ll be highlighting the female athlete triad and how it differs from RED-S. Sign up below to get this right to your mailbox.

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Categories: Megan Kuikman

Megan Kuikman

Hello! I’m Megan Kuikman. I’m a Registered Dietitian with specialized training in sports nutrition. My goal is to help athletes and active individuals achieve a healthy attitude towards health, training, and food. I empower athletes to fuel properly for training in order to restore their health and enhance performance. You can get in touch with me at: hello@megankuikmanRD.ca


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