Raising Awareness of RED-S in Male and Female Athletes and Dancers

Health4Performance is a recently developed BASEM open access educational resource

This is a world premier: a resource developed for and by athletes/dancers, coaches/teachers, parents/friends and healthcare professionals to raise awareness of Relative Energy Deficiency in Sport (RED-S)

What?

Optimal health is required to attain full athletic potential. Low energy availability (LEA) can compromise health and therefore impair athletic performance as described in the RED-S clinical model.

Dietary energy intake needs to be sufficient to cover the energy demands of both exercise training and fundamental physiological function required to maintain health. Once the energy demands for training have been covered, the energy left for baseline “housekeeping” physiological function is referred to as energy availability (EA). EA is expressed relative to fat free mass (FFM) in KCal/Kg FFM.  The exact value of EA to maintain health will vary between genders and individuals, roughly equivalent to resting metabolic rate of the individual athlete/dancer. LEA for an athlete or dancer will result in the body going into “energy saving mode” which has knock on effects for many interrelated body systems, including readjustment to lower the resting metabolic rate in the longer term. So although loss in body weight may be an initial sign, body weight can be steady in chronic LEA due to physiological energy conservation adaptations. Homeostasis through internal biological feedback loops in action.

The most obvious clinical sign of this state of LEA in women is cessation of menstruation (amenorrhea). LEA as a cause of amenorrhoea is an example of functional hypothalamic amenorrhoea (FHA). In other words, amenorrhoea arising as a result of an imbalance in training load and nutrition, rather than an underlying medical condition per se, which should be excluded before arriving at a diagnosis of FHA. All women of reproductive age, however much exercise is being undertaken, should have regular menstrual cycles, which is indicative of healthy hormones. This explains why LEA was first described as the underlying aetiology of the female athlete triad, as women in LEA display an obvious clinical sign of menstrual disruption. The female athlete triad is a clinical spectrum describing varying degrees of menstrual dysfunction, disordered nutrition and bone mineral density. However it became apparent that the clinical outcomes of LEA are not limited to females, nor female reproductive function and bone health in female exercisers. Hence the evolution of the clinical model of RED-S to describe the consequences of LEA on a broader range of body systems and including male athletes.

A situation of LEA in athletes and dancers can arise unintentionally or intentionally. In the diagram below the central column shows that an athlete where energy intake is sufficient to cover the demands from training and to cover basic physiological function. However in the column on the left, although training load has remained constant, nutritional intake has been reduced. This reduction of energy intake could be an intentional strategy to reduce body weight or change body composition in weight sensitive sports and dance.  On the other hand in the column on the right, training load and hence energy demand to cover this has increased, but has not been matched by an increase in dietary intake. In both these situations, whether unintentional or intentional, the net results is LEA, insufficient to maintain health. This situation of LEA will also ultimately impact on athletic performance as optimal health is necessary to realise full athletic potential.

EnergyBalance

Although LEA is the underlying aetiology of RED-S, there are many methodological and financial issues measuring LEA accurately in “free living athletes“. In any case, the physiological response varies between individuals and depends on the magnitude, duration and timing of LEA. Therefore it is more informative to measure the functional responses of an individual to LEA, rather than the value calculated for EA. As such, Endocrine markers provide objective and quantifiable measures of physiological responses to EA. These markers also reflect the temporal dimension of LEA; whether acute or chronic. In short, as hormones exert network effects, Endocrine markers reflect the response of multiple systems in an individual to LEA. So by measuring these key markers, alongside taking a sport specific medical history, provides the information to build a detailed picture of EA for the individual, with dimensions of time and magnitude of LEA. This information empowers the athlete/dancer to modify the 3 key factors under their control of training load, nutrition and recovery to optimise their health and athletic performance.

Slide1

Why?

Who is at risk of developing RED-S? Any athlete involved in sports or dance where being light weight confers a performance or aesthetic advantage. This is not restricted to elite athletes and dancers. Indeed the aspiring amateur or exerciser could be more at risk, without the benefit of a support team present at professional level. Young athletes are at particular risk during an already high energy demand state of growth and development. Therefore early identification of athletes and dancers at risk of LEA is key to prevention of development of the health and performance consequences outlined in the RED-S clinical model. Although there is a questionnaire available for screening for female athletes at risk of LEA, more research is emerging for effective and practical methods which are sport specific and include male athletes.

How?

Early medical input is important as RED-S is diagnosis of exclusion. In other words medical conditions per se need to be ruled out before arriving at a diagnosis of RED-S.  Prompt medical review is often dependent on other healthcare professionals, fellow athletes/dancers, coaches/teachers and parents/friends all being aware and therefore alert to RED-S. With this in mind, the Health4Performance website has areas for all of those potentially involved,  with tailored comments on What to look out for? What to do? Ultimately a team approach and collaboration between all these groups is important. Not only in identification of those at risk of LEA, but in an integrated support network for the athlete/dancer to return to optimal health and performance.

References

Heath4Performance BASEM Educational Resource

Video introduction to Health4Performance website

2018 UPDATE: Relative Energy Deficiency in Sport (RED-S) BJSM 2018

What is Dance Medicine? BJSM 2018

Identification and management of RED-S Podcast 2018

Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists Keay, Francis, Hind. BJM Open Sport and Exercise Medicine 2018

How to Identify Male Cyclists at Risk of RED-S? 2018

Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes IJSNM 2018

Low Energy Availability Is Difficult to Assess but Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes IJSNM 2017

The LEAF questionnaire: a screening tool for the identification of female athletes at risk for the female athlete triad BJSM 2013

IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update BJSM 2018

 

Athletic Fatigue: Part 2

A degree of athletic fatigue following a training session, as described in part 1, is required to set in motion mechanisms to drive beneficial adaptations to exercise. At what point does this process of functional over-reaching tip into non-functional over-reaching denoted by failure to improve sports performance? Or further still along the spectrum and time scale, the chronic situation of overtraining and decrease in performance? Is this a matter of time scale, or degree, or both?

Slide1
Integrated Periodisation of Training Load, Nutrition and Recovery keeps an individual on the green plateau, avoiding descent into the red zone, due to an excess or deficiency

Determining the tipping point between these fatigue situations is important for health and performance. A first step is always to exclude underlying organic disease states, be these of Endocrine, systemic inflammatory or infective aetiologies. Thereafter the crucial step is to assess whether the periodisation of training, nutrition and recovery are integrated over a training block and in the longer term over a training season.

What about the application of Endocrine markers to monitor training load? Although the recent studies described below are more applicable to research scenarios, they give some interesting insights into the interactive networks effects of the Endocrine system and the multifactorial nature of fatigue amongst individual athletes.

In the short term, during a 2 day rowing competition, increases in wakening salivary cortisol were noted followed by return towards baseline in subsequent 2 day recovery. Despite individual variability with salivary cortisol measurement, this does at least offer a noninvasive way to adjust training loads around competition time for elite athletes.

Over an 11 day stimulated training camp and recovery during the sport specific preparatory phase of the training season, blood metabolic and Endocrine markers were measured. In the case of an endurance based training camp in cyclists, a significant increase in urea (due to protein breakdown associated with high energy demand training) and decrease in insulin-like growth factor 1 (IGF1) from baseline were noted. Whereas for the strength-based athletes for ball sports, an increase in creatine kinase (CK) was seen, as a result of muscle damage. This study demonstrates how different markers of fatigue are specific to sport discipline and mode of training. Large inter-individual variability existed between the degree of change in markers and degree of fatigue.

In the longer term, for the case of overtraining syndrome potential Endocrine markers have been reviewed. Whilst basal levels of most measured hormones remained stable, a blunted submaximal exercise response of growth hormone (GH), prolactin and ACTH could be indicative of developing overtraining syndrome. Whilst this review is interesting, dynamic testing is not a practical approach and these findings are not specific to over training. Rather this blunted dynamic exercise response would indicate relative suppression of the neuroendocrine hypothalamic-pituitary axis which could potentially involve other stressors such as inadequate sleep or poor nutrition. Although basal levels may lie “within the normal range”, if both pituitary derived stimulating hormone and end endocrine gland hormone concentrations fall in the lower end of the normal ranges (eg low end of range TSH and T4) this is consistent with mild hypothalamic suppression observed over the range of training and fatigue conditions (functional/non-functional and overtraining) and/or Relative Energy Deficiency in Sports (RED-S).

Although the studies above are of research interest, non invasive monitoring, specific to an athlete is more practical for monitoring the effects of training. Several useful easily measurable metrics can give clues: resting heart rate, heart rate variability, power output. Tools on Strava and Training Peaks provide practical insights in monitoring training effectiveness via these metrics. A range of mobile apps makes it ever easier to augment a personal training log to include these training metrics, along with feel, sleep and nutrition. Such a log provides feedback on health and fitness for the individual athlete, in order to personalise training plans. Certainly adding the results from any standard basal blood tests will also help add to the picture, along the lines of building a longitudinal personal biological passport. After all, “normal ranges” are based on the general population, of which top level athletes may represent a subgroup. The more personalised the metics recorded over a long time scale, the more sensitive and useful the process to guide improvement in sport performance.

Context is key when considering athletic fatigue: temporal considerations and individual variation. Certainly the interactive network effects of the Endocrine system are important in determining the degree of adaptation to exercise and therefore sports performance. However the Endocrine system acts in conjunction with many other systems (metabolic, immune and inflammatory), in determining the effectiveness of training in improving sports performance. So it is not surprising that one metric or marker in isolation is not predictive of fatigue status in individual athletes.

For more discussion on Health, Hormones and Human Performance come to the British Association of Sport and Exercise Medicine annual conference

Presentations

References

Athletic Fatigue: Part 1

Endocrine system: balance and interplay in response to exercise training

Temporal considerations in Endocrine/Metabolic interactions Part 1

Fatigue, sport performance and hormones..more on the endocrine system Dr N Keay, British Journal of Sports Medicine 2017

Sport Performance and RED-S, insights from recent Annual Sport and Exercise Medicine and Innovations in Sport and Exercise Nutrition Conferences Dr N Keay, British Journal of Sports Medicine 2017

Capturing effort and recovery: reactive and recuperative cortisol responses to competition in well-trained rowers British Journal of Sports Medicine

Blood-Borne Markers of Fatigue in Competitive Athletes – Results from Simulated Training Camps Plos One

Hormonal aspects of overtraining syndrome: a systematic review BMC Sports Science, Medicine and Rehabilitation 2017

Clusters of Athletes – A follow on from RED-S blog series to put forward impact of RED-S on athlete underperformance Dr N Keay, British Association of Sport and Exercise Medicine 2017

Strava Fitness and Freshness Science4Performance 2017

From population based norms to personalised medicine: Health, Fitness, Sports Performance Dr N Keay, British Journal of Sports Medicine 2017

Sports Endocrinology – what does it have to do with performance? Dr N Keay, British Journal of Sports Medicine 2017

Clusters of Athletes

 At some time, most athletes experience periods of underperformance. What are the potential causes and contributing factors?

classification

Effective training improves sports performance through a process of adaptation that occurs, at both the cellular and system levels, during the recovery phase. Training overload must be balanced with sufficient subsequent recovery. A long-term improvement in form is expected, following a temporary dip in performance, due to short-term fatigue.

However, when an athlete experiences a stagnation of performance, what are the potential underlying causes? How should these be addressed to prevent an acute situation developing into a more chronic spiral of decreasing performance?

Depending on clinical presentation, the first step is to exclude medical conditions. Potential infective causes include Epstein Barr virus (particularly in young athletes), Lyme disease and Weil’s disease. Systemic inflammatory conditions should be considered. Endocrine and metabolic causes include pituitary, gonadal, adrenal, thyroid  dysfunction, blood sugar control,  and malabsorption.

If medical conditions are excluded, attention should turn to the athlete’s energy balance in the context of adherence to the current training plan. Potential causes of underperformance, the inability to improve in training and competition, are illustrated in the diagram above.

Athletes in the upper right quadrant fail to live up to performance expectations, in spite of maintaining a good energy balance while adhering to the prescribed training plan. However, they may represent non-functional overreaching, where overload is not balanced with sufficient recovery. In other words, the periodisation of training and recovery is not optimised. The balance between chronic training load (fitness) and acute training load (fatigue) provides a useful metric for assessing form. Heart rate variability (HRV) can be another potentially useful measure in detecting aerobic, endurance fatigue. If the training plan is not producing the expected improvements, then this plan needs revising. Don’t forget that sleep is essential to facilitate endocrine driven adaptations to exercise training.

Athletes in the lower right quadrant are of more concern. Inadequate energy balance, especially during periods of increased training load or intentional weight loss, can be a cause of underperformance, despite the athlete being able to adhere to the training plan. This would correspond to being at risk of developing relative energy deficiency in sport (RED-S) on the amber warning in the risk stratification laid out by the International Olympic Committee.

Both of these groups are able to adhere to a training plan, but suboptimal training and recovery periodisation and/or insufficient energy intake can produce a situation of underperformance. Intervention is required to prevent them moving into the clusters on the left, representing a more chronic underperformance scenarios that are therefore more difficult to rectify.

Athletes in the upper left quadrant exhibit overtraining syndrome: a prolonged maladaptation process accompanied by a decrease in performance (not merely stagnation) and inability to adhere to training plan. The metric of decreased HRV and inability of heart rate to accelerate in response to exercise have been suggested as markers of overtraining.

Those athletes in the lower left quadrant fall into the RED-S category, where multiple interacting Endocrine networks are impacted by an energy deficient state. RED-S not only impairs sports performance, but impacts both current and future health. For example low endogenous levels of sex steroids and insulin-like growth factor 1 (IGF1) disrupt formation of bone microarchitecture and bone mineralisation, resulting in increased risk of recurrent stress fracture in addition to potentially irreversible bone loss in the longer term. In cases of recurrent injury and underperformance amongst athletes it is imperative to exclude Endocrine dysfunction and then consider whether RED-S is the fundamental cause.

There are many potential causes of underperformance in athletes. Once medical conditions have been excluded, the main aim should be to prevent acute situations becoming chronic and therefore more difficult to resolve.

For further discussion on Endocrine and Metabolic aspects of SEM come to the BASEM annual conference 22/3/18: Health, Hormones and Human Performance

References

Sport Endocrinology Dr N. Keay, British Journal of Sport Medicine 2017

Sport Performance and RED-S, insights from recent Annual Sport and Exercise Medicine and Innovations in Sport and Exercise Nutrition Conferences Dr N.Keay, British Journal of Sport Medicine 2017

Relative Energy Deficiency in Sport CPD module for British Association of Sport and Exercise Medicine

Optimal Health: For All Athletes! Part 4 – Mechanisms, Dr N. Keay, British Association of Sport and Exercise Medicine

Balance of recovery and adaptation for sports performance Dr N. Keay, British Association of Sport and Exercise Medicine

Sleep for health and sports performance Dr N. Keay, British Journal of Sport Medicine

Optimal health: including female athletes! Part 1 Bones Dr N.Keay, British Journal of Sport Medicine

Inflammation: why and how much? Dr N. Keay, British Association of Sport and Exercise Medicine

Fatigue, Sport Performance and Hormones… Dr N.Keay, British Journal of Sport Medicine

Part 3: Training Stress Balance—So What? Joe Friel

Heart Rate Variability (HRV) Science for Sport

Relative Energy Deficiency in sport (REDs) Lecture by Professor Jorum Sundgot-Borgen, IOC working group on female athlete triad and IOC working group on body composition, health and performance. BAEM Spring Conference 2015.

Prevention, Diagnosis, and Treatment of the Overtraining Syndrome: Joint Consensus Statement of the European College of Sport Science and the American College of
Sports Medicine. Joint Consensus Statement. Medicine & Science in Sports & Exercise 2012