Relative Energy Deficiency in Sports (RED-S) Practical considerations for endurance athletes

EnergyBalance

Introduction Relative Energy Deficiency in Sport (RED-S) has evolved from the previously described Female Athlete Triad (menstrual dysfunction, disordered eating and decreased bone mineral density). The reason for the development of this clinical model of RED-S is that it has become apparent that low energy availability, ie not eating enough calories to support the combined energy demands of health and training, has more widespread adverse impacts on health and consequently performance in athletes and dancers than previously recognised. Furthermore, the RED-S model includes both male and female athletes– so if you are a male athlete, please do not stop reading! Low energy availability can impact male and female exercises of all levels and of all ages. Young developing athletes can be at particular risk of RED-S as this represents a time of growth and development, which entails many nutritional demands, in addition to those to support training. This represents a time to set up the template for health into adulthood.

Why does RED-S occur? RED-S is particularly prevalent in sports where low body weight confers a performance advantage or for aesthetic reasons. For example: long distance running, triathlon, gymnastics, dance and cycle road racing. However, RED-S could also occur not as an intentional strategy to control body weight, but rather during cycles of increased training load where periodised nutrition has not been synchronised with the increased demand on the body.

What is RED-S? Fundamentally there is a mismatch between food intake (in terms of energy and micronutrients) and the demand for nutrition required to cover expenditure, both of exercise training and for basic “housekeeping” tasks in the body to maintain health. If there is insufficient energy availability, then the body switches into an energy saving mode. This “go slow” mode has implications for hormone production and metabolic processes, which impacts all systems throughout the body. The reason why RED-S was originally described as the Female Athlete Triad is that in women the “energy saving mode” involves menstrual periods being switched off: a pretty obvious external sign as all women of child bearing age should have periods (apart from when pregnant). Low oestrogen levels have an adverse effect on bone health, resulting in decrease in bone mineral density. This effectively renders young women at increased risk of both soft tissue and bone injury, as seen in post-menopausal women. As described in the IOC statement published 2014 and updated 2018 in British Journal of Sports Medicine , the Female Athlete Triad is now recognised as just the tip of the iceberg. Disruption of hormone levels does not only adversely impact menstrual periods and bone health. There are knock on effects impacting the immune system, cardiovascular system, muscles, nervous system, gut health and the list goes on. Importantly, it is recognised that this situation is also seen in male athletes: low energy availability resulting in adverse health and performance consequences. Although exercise/dance is known to have many beneficial effects on health, all these beneficial effects are negated by low energy availability. For example, whether or not a sport is weight bearing, which traditionally improves bone health, in RED-S the predominant effect of disrupted hormones is to decrease bone density, leading to increased fracture risk.

Male cyclists Road cyclists are doubly at risk of the detrimental effects of RED-S on bone health. Performing a non-weight bearing form of exercise deprives the skeleton of the positive effect of mechanical skeletal loading on bone health. Furthermore being low body weight is a performance advantage for road cyclists when it comes to riding up hills/mountains in order to produce higher Watts/Kg over 60 minutes (60 minute functional threshold power FTP). This puts cyclists at risk of developing low energy availability, endocrine dysfunction and consequent impairment of bone health. In weight bearing sport the warning sign of suboptimal bone health if often stress fracture. This will be absent in cyclists. Hence low energy availability may go unrecognised until a bike fall results in serious fracture and indeed fractures appears as the most common type of injury amongst cyclists. Furthermore, the lumbar spine is recognised as the site most susceptible to endocrine dysfunction in RED-S. Vertebral fracture is recorded as the type of fracture in cyclists requiring the longest time off the bike. In a recent study, it was found that the factor most indicative of 60 minute FTP, was training load and NOT low body fat. Furthermore, training in low energy availability state will not result in the expected 60 minute FTP performance. So far more effective to train with sufficient nutrition on board, rather than restricting intake which will render training less effective.

What is the significance of RED-S? Do these effects of RED-S matter? Yes: there is a detrimental effect on not only health, but on all elements of sports performance. These include an inability to improve as expected in response to training and increased risk of injury. In the long-term there are potential implications for health with inability to reach peak bone mass for young athletes and at the other end of the scale, irreversible bone loss being seen in retired athletes.

Here is a summary of the potential impact of RED-S:

• Endocrine dysfunction: decreased training response

• Metabolic disruption: decreased endurance performance

• Bone health: increased risk bone stress injuries

• Decreased functional immunity: prone to infection

• Gut malfunction: impaired absorption of nutrients

• Decreased neuromuscular co-ordination: injury risk

• Psychological impact: inability to recognise risk developing RED-S

As you can see, these adverse effects are all relevant to performance in endurance sport.

What to do if you are concerned you may have RED-S?

Health Considerations:

• Women: even if your adult weight is steady, if you are a female athlete of reproductive age whose periods have stopped, then do not ignore this! In the first instance, you need to exclude any other causes (for example polycystic ovary syndrome and other hormone issues) in conjunction with your doctor. Then take a look at how you are eating in line with your training load – see the nutritional considerations section below.

• Men: if you are a male athlete struggling to improve sport performance, then review both your training load and your periodised nutrition and recovery. If the cause is RED-S then do not wait until your sport performance drops or you get injured before taking action. You may also want to consider having your testosterone levels measured to check that these are in the normal range.

Nutritional Considerations: From colleague Jo Scott-Dalgleish BSc (Hons), mBANT, CNHC

It is important to consider whether the energy deficiency that you are experiencing is intentional or unintentional.

Intentional: you may be deliberately restricting your calorie intake to lose weight and body fat, although you are already a healthy weight, as you believe this will improve your power-to-weight ratio or run speed.

  • If you are trying to lose weight – or anxious about gaining weight – and experiencing issues with hormones (such as missing your periods or not experiencing morning erections) or bone health (such as getting a stress fracture) or finding that your performance is declining rather than improving, it may be time to seek support.
  • This is particularly important if your eating patterns have become disordered, eg exclusion of multiple food groups, binge eating and/or purging, or deliberately avoiding social situations around food.
  • Please visit the resources section of an excellent campaign website that has been put together to help athletes talk more openly about their experiences with food, disordered eating and RED-S and find help: https://trainbrave.org/resources/.
  • Another great resource to learn more about RED-S and how it can adversely affect your health is http://health4performance.co.uk/athlete-dancer/

Unintentional: eating fewer calories than your body needs when you are training hard is common in endurance athletes and often not deliberate.

  • You may not yet be experiencing the symptoms of RED-S outlined as above, but you are greatly at risk of doing so if you continue to under-eat relative to your training over a period of months or years.
  • You do not need to be losing weight to be energy deficient, as your body’s metabolism adjusts to a lower intake but compromises on other functions while your weight stays the same. For example, you may experience constipation or bloating due to slowed digestive function. Here are some tips to help you meet your energy needs.

Here are some tips to help you to better manage your energy intake if you are at unintentional risk of RED-S.

  • Track your food intake vs energy expenditure for a short period. Use My Fitness Pal or a similar app to track these daily over the course of week. On any day when you train, if you are consuming fewer than 2500 calories as a male endurance athlete and 2000 calories as a female endurance athlete after taking your energy expenditure through training into account, your intake is likely to be inadequate as these are the guidelines for the general population. Use this data to learn more about appropriate food choices and serving sizes and introduce some changes to increase your intake in line with your training load. But I do not suggest using apps like these on a long-term basis as they may encourage an unhealthy obsession with your food intake.
    • Periodise your carbohydrate intake in line with your training. Increase your intake of starches and sugars (including vegetables and fruit) on your heavier training days. A low daily carbohydrate intake might be in the range of 2-4 g/kg of body weight. This is OK for lower volume training days but should be increased to 5-8 g/kg when training for 2-3 hours or more in a single day. This would include use of sports nutrition products like bars, gels and sports drinks during training. Again, use an app like My Fitness Pal for a week to help you assess your carbohydrate intake.
  • Pay attention to your recovery nutrition. Consuming 15-25g of protein and 45-75g of carbohydrate in the hour after exercise, whether as a snack or as part of a meal will help you to each your energy intake goals, restock your glycogen stores for your next training session and protect lean muscle mass.
  • Avoid excluding foods, whole food groups or following ‘fad diets’. Unless you have a genuine allergy or a diagnosed medical condition such as coeliac disease or lactose intolerance. Or you have been advised to avoid certain foods by a dietician or other well-qualified nutrition practitioner to help manage a health condition such as Irritable Bowel Syndrome. If you are vegetarian or vegan, see my blog here [link to https://www.endurancesportsnutritionist.co.uk/blog/vegan-diets-guide-endurance-athlete/] for tips on ensuring a well-balanced approach.
  • Focus on nutrient density. Make good quality food choices to help you get enough vitamins and minerals as well as carbohydrates, protein, fat and fibre. Try to eat fresh, minimally processed foods rather than too much packaged food, including 3-5 servings of vegetables and 2-3 pieces of fresh fruit each day.

If you are experiencing relative energy deficiency, avoid following approaches like fasted training, where the training benefits are likely to be outweighed by the pitfalls of inadequate calorie intake. I also suggest avoiding low carb-high fat diets (LCHF) due to potential adverse effects on thyroid hormones, particularly T3, which may slow down metabolism and impact on performance. It can also be difficult to obtain adequate calories from these types of diets due to the near exclusion of a whole food group – which is why they may be very effective for weight loss in people who are overweight – and the lack of carbohydrate may harm performance through a loss of metabolic flexibility, ie ability to utilise carbohydrate as fuel when required for high intensity efforts.

Conferences in Sport/Dance, Exercise Science and Medicine 2018

References

Raising Awareness of RED-S in Male and Female Athletes and Dancers Dr N. Keay, British Journal of Sport Medicine 2018

2018 UPDATE: Relative Energy Deficiency in Sport (RED-S) Dr N. Keay, British Journal of Sport Medicine 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 N, Francis G, Hind K. BMJ Open Sport & Exercise Medicine 2018

Optimal health: including female athletes! Part 1 Bones Dr N. Keay, British Journal of Sport Medicine 2017

Optimal health: including male athletes! Part 2 Relative Energy Deficiency in sports Dr N. Keay, British Journal of Sport Medicine 2017

Optimal Health: Especially Young Athletes! Part 3 – Consequences of Relative Energy Deficiency in Sports Dr N. Keay, British Association of Sport and Exercise Medicine 2017

Mechanisms for optimal health…for all athletes! Dr N. Keay, British Journal of Sport Medicine 2017

The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S) British Journal of Sports Medicine 2014

Nutritional considerations for vegetarian endurance athletes Jo Scott-Dalgleish, Endurance Sports Nutrition 2017

 

Temporal considerations in Endocrine/Metabolic interactions Part 1

LifeSeasonDay

It is not a simple question of what, but when we eat, sleep and exercise.

The Endocrine system displays temporal variation in release of hormones. Integrating external lifestyle factors with this internal, intrinsic temporal dimension is crucial for supporting metabolic and Endocrine health.

Amplitude and frequency of hormonal secretion display a variety of temporal patterns:

  • Diurnal variation, synchronised with external light/dark. Orchestrated by a specific area of the hypothalamus, the neuroendocrine gatekeeper.
  • Circadian rhythm, roughly 24-25 hours which can vary with season according to duration of release of melatonin from the pineal gland.
  • Infradian rhythms longer than a day, for example lunar month seen in patterns of hypothalamic-pituitary-ovarian axis hormone release during the menstrual cycle.
  • Further changes in these temporal release and feedback patterns occur over a longer timescale during the lifespan.

Hormones influence gene expression and hence protein synthesis over varying timescales outlined above. The control system for hormone release is based on interactive feedback loops. The hypothalamus is the neuroendocrine gatekeeper, which integrates external inputs and internal feedback.  The net result is to maintain intrinsic biological clocks, whilst orchestrating adaptations to internal perturbations stimulated by external factors such as sleep pattern, nutrition and exercise.

Circadian alignment refers to consistent temporal patterns of sleep, nutrition and physical activity. Circadian misalignment affects sleep-architecture and subsequently disturbs the interaction of metabolic and Endocrine health. This includes gut-peptides, glucose-insulin interaction, substrate oxidation, leptin & ghrelin concentrations and hypothalamic-pituitary-adrenal/gonadal-axes. The main stimuli for growth hormone release are sleep and exercise. Growth hormone is essential for supporting favourable body composition. These integrated patterns of environmental factors may have a more pronounced effect on those with a genetic predisposition or during crucial stages of lifespan. For example curtailed sleep during puberty can impact epigenetic factors such as telomere length and thus may predispose to metabolic disruption in later life. Regarding activity levels, there are strong relationships between time spent looking at screens and markers, such as insulin resistance, for risk of developing type 2 diabetes mellitus in children aged 9 to 10 years.

In addition to adverse metabolic effects set in motion by circadian misalignment, bone turnover has also shown to be impacted. Circadian disruption in young men resulted in uncoupling of bone turnover, with decreased formation and unchanged bone resorption as shown by monitoring bone markers. In other words a net negative effect on bone health, which was most pronounced in younger adult males compared with their older counterparts. These examples underline the importance of taking into account changes in endogenous temporal patterns during the lifespan and hence differing responses to external lifestyle changes.

For male and female athletes, integrated periodised training, nutrition and recovery has to be carefully planned over training seasons to support optimal adaptations in Endocrine and metabolic networks to improve performance. Training plans that do not balance these all these elements can result in underperformance, potentially relative energy deficiency in sport and consequences for health in both short and long term.

Part 2 will consider the longer term consequences and interactions of these temporal patterns of lifestyle factors, including seasonal training patterns in male and female athletes, on the intrinsic biochronometry controlling the Endocrine and metabolic networks during lifespan.

For further discussion on Health, Hormones and Human Performance, come to the BASEM annual conference

References

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

One road to Rome: Metabolic Syndrome, Athletes, Exercise Dr N. Keay

Metabolic and Endocrine System Networks Dr N. Keay

Endocrine system: balance and interplay in response to exercise training Dr N.Keay

Sleep for health and sports performance Dr N.Keay, British Journal of Sports Medicine 2017

Factors Impacting Bone Development Dr N. Keay

Sleep, circadian rhythm and body weight: parallel developments Proc Nutr Soc

Sleep Duration and Telomere Length in Children Journal of Paediatrics 2017

Screen time is associated with adiposity and insulin resistance in children Archives of Disease in Childhood

Circadian disruption may lead to bone loss in healthy men Endocrine today 2017

Successful Ageing Dr N. Keay, British Association of Sport and Exercise Medicine 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

Optimal Health: For All Athletes! Part 4 – Mechanisms Dr N. Keay, British Association of Sport and Exercise Medicine 2017

 

 

 

 

Sport Performance and Relative Energy Deficiency in Sport

performance-potentialThe Holy Grail of any training program is to improve performance and achieve goals.

Periodisation of training is essential in order to maximise beneficial adaptations for improved performance. Physiological adaptations occur after exercise during the rest period, with repeated exercise/rest cycles leading to “super adaptation”. Adaptations occur at the system level, for example cardiovascular system, and at the cellular level in mitochondria. An increase in mitochondria biogenesis in skeletal muscle occurs in response to exercise training, as described by Dr Andrew Philip at a recent conference at the Royal Society of Medicine (RSM). This cellular level adaptation translates to improved performance with a right shift of the lactate tolerance curve.

The degree of this response is probably genetically determined, though further research would be required to establish causal links, bearing in mind the ethical considerations laid out in the recent position statement from the Australian Institute of Sport (AIS) on genetic testing in sport. Dr David Hughes, Chief Medical Officer of the AIS, explored this ethical stance at a fascinating seminar in London. Genetic testing in sport may be a potentially useful tool for supporting athletes, for example to predict risk of tendon injury or response to exercise and therefore guide training. However, genetic testing should not be used to exclude or include athletes in talent programmes. Although there are polymorphisms associated with currently successful endurance and power athletes, these do not have predictive power. There are many other aspects associated with becoming a successful athlete such as psychology. There is no place for gene doping to improve performance as this is both unethical and unsafe.

To facilitate adaptation, exercise should be combined with periodised rest and nutrition appropriate for the type of sport, as described by Dr Kevin Currell at the conference on “Innovations in sport and exercise nutrition”. Marginal gains have a cumulative effect. However, as discussed by Professor Asker Jeukendrup, performance is more than physiology. Any recommendations to improve performance should be given in context of the situation and the individual. In my opinion women are often underrepresented in studies on athletes and therefore further research is needed in order to be in a position to recommend personalised plans that take into account both gender and individual variability. As suggested by Dr Courtney Kipps at the Sport and Exercise Conference (SEM) in London, generic recommendations to amateur athletes, whether male or female, taking part in marathons could contribute to women being at risk of developing exercise associated hyponatraemia.

For innovation in sport to occur, complex problems approached with an open mind are more likely to facilitate improvement as described by Dr Scott Drawer at the RSM. Nevertheless, there tends to be a diffusion from the innovators and early adapters through to the laggards.

Along the path to attaining the Holy Grail of improved performance there are potential stumbling blocks. For example, overreaching in the short term and overtraining in the longer term can result in underperformance. The underlying issue is a mismatch between periodisation of training and recovery resulting in maladapataion. This situation is magnified in the case of athletes with relative energy deficiency in sport (RED-S). Due to a mismatch of energy intake and expenditure, any attempt at increase in training load will not produce the expected adaptations and improvement in performance. Nutritional supplements will not fix the underlying problem. Nor will treatments for recurrent injuries. As described by Dr Roger Wolman at the London SEM conference, short term bisphosphonante treatment can improve healing in selected athletes with stress fractures or bone marrow lesions.  However if the underlying cause of drop in performance or recurrent injury is RED-S, then tackling the fundamental cause is the only long term solution for both health and sport performance.

Network effects of interactions lead to sport underperformance. Amongst underperforming athletes there will be clusters of athletes displaying certain behaviours and symptoms, which will be discussed in more detail in my next blog. In the case of RED-S as the underlying cause for underperformance, the most effective way to address this multi-system issue is to raise awareness to the potential risk factors in order to support athletes in attaining their full potential.

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

Teaching module RED-S British Association Sport and Exercise Medicine

From population based norms to personalised medicine: Health, Fitness, Sports Performance Dr N. Keay, British Journal of Sport Medicine 22/2/17

Balance of recovery and adaptation for sports performance Dr N. Keay, British Association Sport and Exercise Medicine 21/1/17

Sleep for health and sports performance Dr N. Keay, British Journal of Sport Medicine 7/7/17

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

Annual Sport and Exercise Medicine Conference, London 8/3/17

Bisphosphonates in the athlete. Dr Roger Wolman, Consultant in Rheumatology and Sport and Exercise Medicine, Royal National Orthopaedic Hospital

Collapse during endurance training. Dr Courtney Kipps, Consultant in Sport and Exercise Medicine. Consultant to Institute of Sport, medical director of London and Blenheim Triathlons

Innovations in Sport and Exercise Nutrition. Royal Society of Medicine 7/3/17

Identifying the challenges: managing research and innovations programme. Dr Scott Drawer, Head of Performance, Sky Hub

Exercise and nutritional approaches to maximise mitochondrial adaptation to endurance exercise. Dr Andrew Philip, Senior Lecturer, University of Birmingham

Making technical nutrition data consumer friendly. Professor Asker Jeukendrup, Professor of Exercise Metabolism, Loughborough University

Innovation and elite athletes: what’s important to the applied sport nutritionists? Dr Kevin Currell, Director of Science and Technical Development, The English Institute of Sport

Genetic Testing and Research in Sport. Dr David Hughes, Chief Medical Officer Australian Institute of Sport. Seminar 10/3/17

Effects of adaptive responses to heat exposure on exercise performance

Over Training Syndrome, Ian Craig, Webinar Human Kinetics 8/3/17

The Fatigued Athlete BASEM Spring Conference 2014

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.

Mountjoy M, Sundgot-Borgen J, Burke L, Carter S, Constantini N, Lebrun C, Meyer N, Sherman R, Steffen K, Budgett R, Ljungqvist A. The IOC consensus statement: beyond the Female Athlete Triad-Relative Energy Deficiency in Sport (RED-S).Br J Sports Med. 2014 Apr;48(7):491-7.