Relative energy deficiency syndrome (RED-S) is a combination of symptoms experienced by athletes secondary to a chronic low energy availability. This means that our bodies have insufficient energy for normal functioning leading to a host of symptoms including impaired bone development and loss of menstruation. After reading this article my hope is that you will have a better understand of what RED-S is and how it can be identified.
RED-S is a syndrome associated with poor energy availability but what does that mean?
Energy availability is the amount of energy your body can utilise once the energy expended during exercise has been considered. Therefore, it is the energy your body can use to fuel physiological functioning. This includes energy to maintain metabolism, bone health, menstrual function, immune functioning, and cardiovascular health, all of which are essential for good health. If we are not fuelling our bodies sufficiently all these functions can be impaired, impacting our health.
Energy availability is calculated as total intake minus energy used for exercise divided by fat free mass. Fat free mass is our lean body mass and not our total body weight. It is advised that for normal body functions we need an energy availability of 45kcal/kg fat free mass. This means that we need to consume this amount of energy in addition to the energy that will be burnt during training. Therefore, if you are training frequently and burning a lot of energy, a low energy intake may have significant impacts on your health.
RED-S was previously known as the Female Athlete Triad which was characterised by low energy availability, loss of menstruation and low bone density. This name was been changed by the International Olympic Committee in 2014 to recognise that this is not solely an issue in women but that male athletes can also suffer from RED-S. In males the main health effect in men is impaired bone development. Low bone density increases risk of fractures. However, amenorrhea, loss of menses, often occurs prior to fractures meaning that female athletes may be diagnosed and treated for RED-S earlier than male athletes.
Why does a low energy availability impact bone health?
It is related to hormonal imbalance. With inadequate energy our bodies make less hormones. In women oestrogen concentrations drop which reduces calcium deposition to bones. In males, testosterone concentrations decrease which is also involved in bone formation. In the absence of these hormones due to chronic low energy availability, bone density decreases causing weakening of the bones.
The low oestrogen concentrations due to low energy availability also have significant impacts on female reproductive health. Athletes with low energy availability may experience amenorrhea. Amenorrhea is diagnosed based on the absence of three consecutive menstrual cycles. It is important to remember that missing periods is not healthy and should be investigated. It may be a sign that you are not having sufficient energy to fuel your body. In female athletes contraceptive use can mask loss of menses making it more difficult to identify RED-S at an early stage.
Of course, in addition to the long-term health effects of RED-S impairments in performance can also be seen. With insufficient energy intake you may have lower concentration levels, increased risk of injury, reduced strength, reduced adaptation to training, and reduced muscle glycogen stores which are required for muscle contraction during exercise. You may notice a difference in your performance prior to loss of menstruation or reduced bone mass. Therefore, if you notice a difference in how you are performing it is important to consider if you are fuelling your body appropriately to not only meet your energy needs for training but also that to maintain healthy physiological functioning.
So with all of this in mind, what are the main things to look out for in identifying RED-S?
1. Loss of periods
2. Stress fractures and injuries
3. Increased illness
4. Impaired performance
If you think you have RED-S what should you do?
Speak to your GP and get an appointment booked in with a sports physician and sports dietitian. Treatment for RED-S involves increasing energy intake to fuel your body, reductions in energy expenditure from exercise, or sometimes a combination of both. The length of time to restoration of menses will be dependent on the length of time of menstrual dysfunction along with the extent of energy deficiency. With increases in energy availability bone formation will also be restored.
Speaking to a Registered Dietitian can help you to ensure you meet your energy requirements preventing impacts on performance and long-term health effects. The earlier on we have an intervention, the better the results.
Book your free discovery call, by clicking HERE or book your 1-1 nutrition consultation by clicking HERE.
We look forward to helping you in your journey.