I recently published a paper in the International Journal of Sports Nutrition and Exercise Metabolism outlining how to treat relative energy deficiency in Sport (RED-S) using nonpharmacological strategies alongside Dr. Margo Mountjoy, Dr. Trent Stellingwerff, and Dr. Jamie Burr. If you would like to read the paper, click here. For those that don’t love reading scientific writing, I have summarized the findings of the paper below.

While we all know that sport and exercise is generally good for us, in some situations it can result in negative impacts on health and performance. While this is certainly the exception, not the norm, this may occur when athletes or active individuals over-exercise or consume too few calories. While insufficient caloric intake can in-and-of itself result in a state of low energy availability and challenges to good health, it can also be associated with the syndrome of relative energy deficiency in sport (RED-S), wherein athletes under-eat relative to the amount of energy they expend through training and competition. RED-S is defined by a set of symptoms that has various health and performance implications (for more on RED-S, click here). This may include missing periods in females, poor bone health, repeated injuries and illness and a slowed metabolism. Treatment of RED-S is critical to prevent these outcomes, which can have devastating implications for an athlete’s health and performance.

While low energy availability is the underlying cause of RED-S, treatment is not as simple as achieving an “optimal” level of energy availability. Calculating an athlete’s daily energy availability requires knowing how many calories an athlete is consuming, how many calories an athlete is expending during exercise and an athlete’s fat free mass. Measuring calories consumed and calories expended is time consuming and prone to error, while determining an athlete’s fat free mass requires access to expensive specialized equipment and expertise. This makes calculating energy availability outside of a laboratory setting unrealistic and is further complicated by the fact that there is no validated threshold of energy availability that is “optimal” for an athlete’s health. It’s important to note that mismatches in energy intake versus expenditure are not always conscious decisions, and in-fact the athlete may not have recognized the imbalance when training load is increased, or appetite naturally supressed.

As achieving a specific threshold of energy availability is not recommended for treating RED-S, treatment should instead focus more broadly on an athlete increasing their calorie intake. In some situations, a reduction in exercise may also be necessary in order to restore an athlete’s health. The amount that an athlete should increase their caloric intake needs to be individualized. This requires assessment by a Registered Dietitian, who can evaluate an athlete’s current food intake and make recommendations accordingly.

While fixing the underlying energy deficit is necessary in the treatment of RED-S, there is evidence for interventions that target factors that may make the health and performance outcomes of RED-S worse. Below, these interventions are highlighted.

Timing of calorie intake: Not only should total calorie intake be considered when treating an athlete with RED-S, but also the timing of calorie intake in order to minimize the amount of time spent in a calorie deficit, with consideration of when in a day the workout occurs. To reduce the number of hours throughout the day that is spent in a calorie deficit, athletes should be educated on consuming breakfast upon waking, eating regular meals and snacks throughout the day, and fuelling properly around training sessions wherein significant calories are expended.

Carbohydrate intake: Many athletes fail to consume enough carbohydrates to support daily training demands. This may have negative implications for bone health and immunity, independent of the number of calories consumed. Based on the initial assessment of an athlete’s diet, athletes may benefit from increasing caloric intake through the consumption of carbohydrate rich foods. In particular, athletes should consume adequate carbohydrates around training sessions, so that exercise is performed with sufficient carbohydrate stores.

Fibre intake: High levels of fibre intake may make an athlete feel full, and as a result, make it hard for an athlete to eat sufficient calories. In addition to this, there is evidence that high levels of fibre intake may reduce levels of the sex hormone, estrogen, in females. This may have negative implications for the menstrual cycle. Based on the initial assessment of an athlete’s diet, an athlete with RED-S may benefit from reducing the consumption of high fibre foods and replacing these foods with more calorie dense foods.

Bone building nutrients: There are various nutrients that play a role in keeping bones healthy, such as calcium, protein, magnesium, phosphorus, vitamin D, potassium, and fluoride. As food is a poor source of vitamin D, an athlete with RED-S may benefit from a blood test to assess vitamin D levels. Many athletes, especially those with little sun exposure, may require a vitamin D supplement to meet daily needs. There is also evidence to suggest that consuming ~1 g calcium prior to and throughout a bout of exercise that results is significant sweat loss, may help to prevent bone breakdown that occurs after exercise.

Mechanical bone stress: The addition of strength or resistance exercise to an athlete’s existing training program may help to improve an athlete’s bone mineral density. This can be particularly useful for athletes who participate in sports that do not involve weight bearing exercise, such as cycling or swimming. However, it is important that any incorporation of strength or resistance training into an existing exercise program be done with a concurrent increase in calorie intake.

Stress management: Psychogenic stress may contribute to the development of RED-S, and inadequate calorie intake may worsen psychological consequences. Cognitive behavioural therapy that addresses psychogenic stress may help reduce stress signals that worsen the health outcomes of RED-S. Independent of the effect on stress signals, cognitive behavioural therapy may help athletes implement the lifestyle changes that are needed to treat RED-S.

RED-S is a serious condition with immediate and long-lasting health and performance outcomes. The treatment of RED-S involves increasing energy intake, and in some situations, reducing exercise rather than achieving a specific level of energy availability. Based on an athlete’s initial assessment, RED-S treatment could also focus on the timing of calorie intake, carbohydrate intake, fibre intake, intake of bone-building nutrients, mechanical bone stress, and/or psychogenic stress. These interventions all impact important physiological mechanisms that can help restore health and performance in an athlete with RED-S.

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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