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

 

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

Relative energy deficiency in sport (RED-S) is a clinical model that describes the potential adverse health and performance consequences of low energy availability (LEA) in male and female athletes. Identification of athletes at risk of LEA can potentially prevent these adverse clinical outcomes.

Athletes at risk of RED-S are those involved in sports where low body weight confers a performance or aesthetic advantage. In the case of competitive road cycling, being light  weight results in favourable power to weight ratio to overcome gravity when cycling uphill. How can male cyclists at risk of LEA be effectively identified in a practical manner?

Energy availability (EA) is defined as the residual energy available from dietary intake, once energy expenditure from exercise training has been subtracted. This available energy is expressed as KCal/Kg fat free mass (FFM). A value of 45 KCal/Kg FFM is roughly equivalent to basal metabolic rate, in other words the energy required to sustain health. In order to quantify EA, accurate measurements of energy intake and expenditure, and FFM assessed from dual X ray absorptiometry (DXA), need to be undertaken. However this is not practical or feasible to undertake all these measurements outside the research setting. Furthermore, methodology for assessing energy intake and expenditure is laborious and fraught with inaccuracies and subjectivity in the case of diet diaries for “free living athletes“. Even if a value is calculated for EA, this is only valid for the time of measurement and does not give any insights into the temporal aspect of EA. Furthermore, an absolute EA threshold has not been established, below which clinical symptoms or performance effects of RED-S occur.

Self reported questionnaires have been shown to be surrogates of low EA in female athletes. However there are no such sport specific questionnaires, or any questionnaires for male athletes. Endocrine and metabolic markers have been proposed as quantitative surrogate measures of EA and shown to be linked to the RED-S clinical outcome of stress fractures in runners. In female athletes the clinical sign of regular menstruation demonstrates a functioning H-P ovarian axis, not suppressed by LEA. What about male athletes? Although hypothalamic suppression of the reproductive axis due to LEA can result in low testosterone, high training loads, in presence of adequate EA, can lead to the same negative effect on testosterone concentration.

Sam

Male cyclists present a further level of complexity in assessing EA status. In contrast to runners, stress fracture will not be an early clinical warning sign of impaired bone health resulting from low EA. Furthermore cyclists are already at risk of poor bone health due to the non weight bearing nature of the sport. Nevertheless, traumatic fracture from bike falls is the main type of injury in cycling, with vertebral fracture requiring the longest time off the bike. Chris Boardman, a serial Olympic medal winner in cycling, retired in his early 30s with osteoporosis. In other words, in road cycling, the combined effect of the lack of osteogenic stimulus and LEA can produce clinically significant adverse effects on bone health.

What practical clinical tools are most effective at identifying competitive male cyclists at risk of the health and performance consequences of LEA outlined in the RED-S model? This was the question our recent study addressed. The lumbar spine is a skeletal site known to be most impacted by nutrition and endocrine factors and DXA is recognised as the “gold standard” of quantifying age matched Z score for bone mineral density (BMD) in the risk stratification of RED-S. What is the clinical measure indicative of this established and clinically significant sign of RED-S on lumbar spine BMD? Would it be testosterone concentration, as suggested in the study of runners? Another blood marker? Cycle training load? Off bike exercise, as suggested in some previous studies? Clinical assessment by interview?

Using a decision tree approach, the factor most indicative of impaired age matched (Z score) lumbar spine BMD was sport specific clinical assessment of EA. This assessment took the form of a newly developed sports specific energy availability questionnaire and interview (SEAQ-I). Reinforcing the concept that the most important skill in clinical medical practice is taking a detailed history. Questionnaire alone can lead to athletes giving “correct” answers on nutrition and training load. Clinical interview gave details on the temporal aspects of EA in the context of cycle training schedule: whether riders where experiencing acute intermittent LEA, as with multiple weekly fasted rides, or chronic sustained LEA with prolonged periods of suppressed body weight. Additionally the SEAQ-I provided insights on attitudes to training and nutrition practices.

Cyclists identified as having LEA from SEAQ-I, had significantly lower lumbar spine BMD than those riders assessed as having adequate EA. Furthermore, the lowest lumbar spine BMD was found amongst LEA cyclists who had not practised any load bearing sport prior to focusing on cycling. This finding is of particular concern, as if cycling from adolescence is not integrated with weight bearing exercise and adequate nutrition when peak bone mass (PBM) is being accumulated, then this risks impaired bone health moving into adulthood.

Further extension of the decision tree analysis demonstrated that in those cyclists with adequate EA assessed from SEAQ-I, vitamin D concentration was the factor indicative of lumbar spine BMD. Vitamin D is emerging as an important consideration for athletes, for bone health, muscle strength and immune function. Furthermore synergistic interactions with other steroid hormones, such as testosterone could be significant.

What about the effects of EA on cycling performance? For athletes, athletic performance is the top priority. In competitive road cycling the “gold standard” performance measure is functional threshold power (FTP) Watts/Kg, produced over 60 minutes. In the current study, 60 minute FTP Watts/Kg had a significant relationship to training load. However cyclists in chronic LEA were under performing, in other words not able to produce the power anticipated for a given training load. These chronic LEA cyclists also had significantly lower testosterone concentration. Periodised carbohydrate intake for low intensity sessions is a strategy for increasing training stimulus. However if this acute intermittent LEA is superimposed on a background of chronic LEA, then this can be counter productive in producing beneficial training adaptations. Increasing training load improves performance, but this training is only effective if fuelling is tailored accordingly.

Male athletes can be at risk of developing the health and performance consequences of LEA as described in the RED-S clinical model. The recent study of competitive male road cyclists shows that a sport specific questionnaire, combined with clinical interview (SEAQ-I) is an effective and practical method of identifying athletes at risk of LEA. The temporal dimension of LEA was correlated to quantifiable health and performance consequences of RED-S.

References 

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, BMJ Open in Sport and Exercise Medicine 2018

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

Fuelling for Cycling Performance Science4Performance

Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes International Journal of Sport Nutrition and Exercise Metabolism 2018

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

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

Low Energy Availability Is Difficult to Assess but Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes International Journal of Sport Nutrition and Exercise Metabolism 2018

Treating exercise-associated low testosterone and its related symptoms The Physician and Sports Medicine 2018

Male Cyclists: bones, body composition, nutrition, performance Keay, BJSM 2018

Cyclists: Make No Bones About It Keay, BJSM 2018

Male Athletes: the Bare Bones of Cyclists

Cyclists: How to Support Bone Health?

Synergistic interactions of steroid hormones Keay BJSM 2018

Fuel for the Work Required: A Theoretical Framework for Carbohydrate Periodization and the Glycogen Threshold Hypothesis Sports Medicine 2018

 

What is Dance Medicine?

Traditionally dance medicine has been somewhat the poor relation of sports medicine. Why is this the case? There is no doubt that dancers, of whatever genre, require the physical and psychological attributes of athletes. However, dance involves an additional artistic component where ultimately performance on stage is judged not according to a score card as in aesthetic sports, rather on the ability of the dancers to forge an emotional connection with the audience.

As with athletes, injuries are always an important topic for dancers: how to recognise the aetiology of injuries and thus develop prevention strategies. Dance UK have published two reports on national enquiries into the health of dancers. Dance UK has now evolved into the organisation One Dance which includes the National Institute of Dance Medicine and Science (NIDMS). One Dance provides delivery of the Healthier Dancer Programme (HDP) whose talks regularly engage 1500+ dancers and dance professionals per year and which will be a part of the One Dance UK conference at the end of November, an overarching event for the entire dance sector. One Dance holds a list of healthcare professionals with experience and expertise in dance. One Dance is an especially an important resource for independent dancers who will not have access to the provision for those working in larger dance companies.

However, beyond injury management, there are important aspects of the health of dancers which need to be considered, highlighted in an information booklet “Your body, Your risk” from Dance UK. The female athlete triad is well established as a clinical spectrum comprising of disordered eating, menstrual dysfunction and impaired bone health. Indeed impaired bone mineral density many persist even after retirement in female dancers. The recent evolution of the female athlete triad into relative energy deficiency in sports (RED-S) provides an important clinical model. RED-S includes male athletes/dancers, involves multiple body systems and crucially, evidence of detrimental effects on athletic performance is being researched and described. In other words RED-S is not restricted to female dancers/athletes with bone stress injuries.

BalletDials
Integrated periodisation of training, nutrition and recovery support perforamnce

The fundamental cause of RED-S is low energy availability where nutritional intake is insufficient to cover energy requirements for training and resting metabolic rate. In this situation the body goes into energy saving mode, which includes shut down of many hypothalamic-pituitary axes and hence endocrine network dysfunction. As hormones are crucial to backing up adaptations to exercise training, dysfunction will therefore have an effect not just on health, but on athletic performance. In dance, neuromuscular skills and proprioception are key for performance. Hence, of concern is that these skills are adversely impacted in functional hypothalamic amenorrhoea, which together with impaired bone health from RED-S, greatly increases injury risk.

Low energy availability can arise in dance and sport where low body weight confers an aesthetic and/or performance advantage. There is no doubt that being light body weight facilitates pointe work in female dancers and ease of elevation in male dancers. Thus, low energy availability can occur intentionally in an effort to achieve and maintain low body weight. Low energy availability can also be unintentional as a result of increased expenditure from training, rehearsal and performance demands and the practicality of fuelling. This situation is of particular concern for young dancers in training, as this represents a high energy demand state, not just for full time training, additionally in terms of energy demands for growth and development, including attainment of peak bone mass.

Despite the significance of RED-S in terms of negative consequences on health and performance, as outlined by the IOC in the recent consensus update, further work is required in terms of raising awareness, identification and prevention. Fortunately these issues are being addressed with the development of an online educational resource on RED-S for athletes/dancers, their coaches/teachers/parents and healthcare professionals which is backed by British Association of Sport and Exercise Medicine (BASEM) and with input from One Dance and NIDMS. In terms of research to facilitate the proliferation of evidence base in dance medicine, One Dance lists calls for research, whilst NHS NIDMS clinics provide access to clinical dance medicine. The importance of the application of this growing field of dance medicine and science for the health and performance of dancers was recently outlined in an article “Raising the barre: how science is saving ballet dancers“.

On the international stage, the International Association for Dance Medicine & Science (IADMS) strives to promote an international network of communication between dance and medicine. To this end, IADMS will hold its 28th Annual Conference in Helsinki, Finland from October 25-28, 2018. In addition to extensive discussion of dance injuries, there will be presentations on “Sleep and Performance” and “Dance Endocrinology”.

So maybe Dance Medicine and Science is not so much the poor relation of Sports Medicine, rather showing the way in terms of integrating input between dancers, teachers and healthcare professionals to optimise the health of dancers and so enable dancers to perform their full potential.

References

Presentations

Fit to Dance? Report of National inquiry into dancers’ health.

Fit to Dance 2 Dance UK

One Dance

Your body your risk. Dance UK

Fit but fragile. National Osteoporosis Society

Bone mineral density in professional female dancers N. Keay, BJSM

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

Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes Medicine and Science in Sports & Exercise 2017

Dancing through Adolescence Dr N Keay BJSM

Healthy Hormones Dr N Keay BASEM 2018

Dancers, Periods and Osteoporosis, Keay N, Dancers, Periods and Osteoporosis, Dancing Times, September 1995, 1187-1189

A study of Dancers, Periods and Osteoporosis, Keay N, Dance Gazette, Issue 3, 1996, 47

Raising the barre: how science is saving ballet dancers The Guardian 2018

International Association for Dance Medicine and Science Medicine & Science in Sports and Exercise

 

 

Relative Energy Deficiency in Sport (RED-S) 2018 update

What updates are presented in the IOC consensus statement on RED-S 2018?

Prevention

Awareness is the key to prevention. Yet RED-S continues to go unrecognised. Less than 50% of clinicians, physiotherapists and coaches are reported as able to identify the components of the female athlete triad. In a survey of female exercisers in Australia, half were unaware that menstrual dysfunction impacts bone health. Note that these concerning statistics relate to the female athlete triad. Lack of awareness of RED-S in male athletes is even more marked. RED-S as a condition impacting males, as well as females, was described in the initial IOC consensus statement published in 2014. However there is evidence of the occurrence of RED-S in male athletes pre-dating this.

Identification

Identifying an athlete/dancer with RED-S is not always straight forward. In dance or sports where being light weight confers a performance or aesthetic advantage, how can a coach/teacher distinguish between athletes who have this type of physique “naturally” and those who have disordered eating and are at risk of RED-S?  Equally, low energy availability could be a result either of intentional nutrition restriction to control body weight and composition, or an unintentional consequence of not matching an increase in energy expenditure (due to increased training load), with a corresponding increase in energy intake.

Performance effects

Performance is paramount to any athlete or dancer. Apart from physical ability, being driven and determined are important characteristics to achieve success. If weight loss is perceived as achieving a performance advantage, then this can become a competitive goal in its own right: in terms of the individual and amongst teammates. This underlies the interactive effect of psychological factors in the development and progression in the severity of RED-S.

There is both theoretical and practical evidence that short term low energy availability impairs athletic performance as the body is less able to undertake high quality sessions and benefit from the physiological adaptations to exercise. Within day energy deficits have been shown to have adverse effects in both male and female athletes in terms of impact on oestradiol/testosterone and cortisol concentrations. Failure to refuel with carbohydrate and protein promptly after a training session in male runners has been shown to have an adverse effect on bone turnover markers.

To underline the adverse performance effect of low energy availability, a recent study demonstrated that in female athletes, those with functional hypothalamic amenorrhea displayed decreased neuromuscular performance compared to their eumenorrhoeic counterparts. This adverse effect on performance is of particular concern where such skills are crucial in precisely those sports/dance where RED-S is most prevalent. Clearly this situation puts such athletes at increased injury risk, especially if associated with adverse bone mineral density (BMD) due to low energy availability.

Ironically the long term consequences of low energy availability produce adverse effects on body composition: increased fat/lean and reduction in BMD. In other words, the precise opposite effects of what an energy restricted athlete is trying to achieve. In terms of bone health, the lumbar spine is most sensitive to nutrition/endocrine factors (apart from rowers where mechanical loading can attenuate BMD loss at this site in RED-S). Suboptimal BMD is associated with an increased risk of bone injury and therefore impaired performance.

REDs
Keay BJSM 2017

Medical Assessment

Low energy availability is the fundamental issue driving the multi-system dysfunction in the endocrine, metabolic, haematological, cardiovascular, gastrointestinal, immunological and psychological systems in RED-S. However, there are practical issues with directly quantifying energy availability as this is subject to the inaccuracies of reliably measuring energy intake and output. Endocrine and metabolic markers have been shown to more objective indicators of low energy availability, which in turn are correlated to performance outcomes such as bone stress injury in male and female athletes. In the case of female athletes there is an obvious clinical indicator of sufficient energy availability: menstrual cycles. As there is no such obvious clinical sign in male athletes is this why RED-S is less frequently recognised? In both female and male athletes there is some degree of clinical variation: there is no absolute threshold cut off with a set temporal component of low energy availability resulting in amenorrhoea or low testosterone in males. Therefore the IOC recommends that individual clinical evaluation include discussion of nutrition attitudes and practices, combined with menstrual history for females and endocrine markers for male and female athletes will give a very clear indication if an athlete is at risk of/has RED-S.

 

Management

RED-S is a diagnosis of exclusion. Once medical conditions per se have been excluded, RED-S presents a multi-system dysfunction caused by a disrupted periodisation of nutrition/training/recovery. For an athlete the motivation to address these imbalances is to be in a position reach their full athletic potential. This attainment is compromised in RED-S.

Pharmacological interventions are not recommended as first line management in amenorrhoeic athletes. Oral contraception (OCP) masks amenorrhoea with withdrawal bleeds. OCP does not support bone health and indeed may exacerbate bone loss by suppressing further IGF-1. Although transdermal oestrogen, combined with cyclic progesterone does not down regulate IGF-1, nevertheless any hormonal intervention cannot be a long term solution, as bone loss will continue if energy availability is not addressed as a priority.

What next?

The IOC statement suggests further research should include studies with allocation of athletes to intervention groups, with assessment of effects over a substantial time period. Currently a study of competitive male road cyclists over a training/competition season is being undertaken to evaluate the effects of nutrition advice and off bike skeletal loading exercise. Crucially outcome measures will not only be based on bone health and endocrine markers, but measures of performance in terms of power production and race results.

To raise awareness and build support pathways as recommended in the IOC statement,  this is an on going process which requires communication between athlete/dancers, coaches/teachers, parents and healthcare professionals both medical and non medical working with male and female athletes.

References

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

Male Cyclists: bones, body composition, nutrition, performance BJSM 2018

Male Athletes: the Bare Bones of Cyclists

Addiction to Exercise – what distinguishes a healthy level of commitment from exercise addiction? BJSM 2017

Sports Endocrinology – what does it have to do with performance? BJSM 2017

Within‐day energy deficiency and reproductive function in female endurance athletes Scandinavian Journal of Science and medicine in Sports 2017

The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism Translational Journal of the American College of Sports Medicine 2017

Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes Medicine & Science in Sports & Exercise. 49(12):2478–2485, DEC 2017

Cumulative Endocrine Dysfunction in Relative Energy Deficiency in Sport (RED-S) BJSM 2018

Cyclists: Make No Bones About It BJSM 2018

Low Energy Availability is Difficult to Assess But Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes Sports Nutrition and Exercise Metabolism 2017

Part 2: Health, Hormones and Human Performance take centre stage BJSM 2018

Cyclists: How to Support Bone Health?

Healthy Hormones BASEM 2018

 

 

 

Synergistic Interactions of Steroid Hormones

Slide1

The action of the sun on skin is the most effective way of making vitamin D. However, even walking around outside naked for 5 hours every day during UK winter months is not sufficient to make adequate vitamin D. Therefore, much to the relief of the audience at the recent BASEM Spring conference, this was not a strategy recommended by Dr Roger Wolman.

Vitamin D is a fat soluble steroid hormone. The majority of which is synthesised in the skin when exposed to ultraviolet B in sunlight, with a small contribution from dietary sources: this vitamin D3 molecule is then hydroxylated twice in the liver and then kidney to produce the metabolically active form of vitamin D. This activated steroid hormone binds to vitamin D receptors in various tissues to exert its influence on gene expression in these cells. The mono hydroxylated form of vitamin D is measured in the serum, as this has a long half life.

Does it matter having low levels of circulating vitamin D during winter months? What are the solutions if moving to warmer climates during the winter is (unfortunately) not feasible? What are the other hormones interact with vitamin D?

What are the beneficial effects of vitamin D, particularly in the athletic population?

Bone

Rickets and osteomalacia are conditions where vitamin D deficiency results in bone deformities and radiographic appearances are characterised by Looser zones, which in some ways are similar in appearance to stress fractures.

In a large prospective study of physically active adolescent girls, stress fracture incidence was found to have an inverse relationship with serum vitamin D concentrations. In adult female Navy recruits monitored during an 8 week training programme, those on vitamin D supplementation had a 20% reduction in stress fracture. However, oestrogen status was a more powerful risk factor at 91% in those recruits reporting amenorrhoea. Vitamin D is, itself, is a steroid hormone with range of systemic effects. As will be discussed below, its interaction with the sex steroid oestrogen has an important effect on bone turnover.

Immunity

Although sanatoriums, for those suffering with tuberculosis, were based on providing patients with fresh air, any beneficial effect was probably more due to vitamin D levels being boosted by exposure to sunlight. Certainly there are studies demonstrating the inhibitory effect of vitamin D on on slow growing mycobacteria, responsible for TB. What about the influence of vitamin D on other types of infection? In a recent publication, evidence was presented that supplementation with vitamin D prevented acute respiratory tract infections. This effect was marked in those with pre-existing low levels of vitamin D. In a study of athletes a concentration of 95 nmol/L was noted at the cut off point associated with more or less than one episode of illness. In another randomised controlled study of athletes, those supplemented with 5,000IU per day of vitamin D3 during winter displayed higher levels of serum vitamin D and had increased secretion of salivary IgA, which could improve immunity to respiratory infections.

Muscle

There is evidence that supplementing vitamin D3 at 4,000IU per day has a positive effect on skeletal muscle recovery in terms of repair and remodelling following a bout of eccentric exercise. In the longer term, dancers supplemented with 2,000IU over 4 months reported not only reduction in soft tissue injury, but an increase in quadriceps isometric strength of 18% and an increase of 7% in vertical jump height.

Synergistic actions of steroid hormones

No hormone can be considered in isolation. This is true for the network interaction effects between the steroid hormones vitamin D and oestrogen. In a study of professional dancers, there was found to be significant differences in serum vitamin D concentrations in dancers from winter to summer and associated reciprocal relationship with parathyroid hormone (PTH). In situations of vitamin D deficiency this can invoke secondary hypoparathyroidism. Although low levels of vitamin D were observed in the dancers, this was not a level to produce this condition. However, there was an increase in soft tissue injury during the winter months that could, in part, be linked to low vitamin D levels impacting muscle strength.

The novel finding of this study was that female dancers on the combined oral contraceptive pill  (OCP) showed significant differences, relative to their eumenorrhoeic counterparts not on the OCP, in terms of higher levels of vitamin D and associated reductions of bone resorption markers and PTH. The potential mechanism could be the induction by the OCP of liver enzymes to increase binding proteins that alter the proportion of bound/bioactive vitamin D.

This interaction between steroid hormones oestrogen and vitamin D could be particularly significant in those in low oestrogen states such as postmenpoausal women and premenarchal girls. Menarche can be delayed in athletes, so is there a case for vitamin D supplementation in young non-menstruating athletes? What is the situation for men? Do testosterone and vitamin D have similar interactions and therefore implications for male athletes with RED-S, where testosterone can be low?

Vitamin D is not simply a vitamin. It is a steroid hormone with multi-system effects and interactions with other steroid hormones, such as sex steroids, which are of particular relevance to athletes.

References

BASEM Spring Conference 2018 “Health, Hormones and Human Performance”

BASEM Spring Conference 2018 Part 2 “Health, Hormones and Human Performance”

Calcium and Vitamin D Supplementation Decreases Incidence of Stress Fractures in Female Navy Recruits JBMR 2009

Vitamin D, Calcium, and Dairy Intakes and Stress Fractures Among Female Adolescents Arch Pediatr Adolesc Med 2012

A Single Dose of Vitamin D Enhances Immunity to Mycobacteria American Journal of Respiratory and Critical Care Medicine 2007

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data BMJ 2017

Influence of vitamin D status on respiratory infection incidence and immune function during 4 months of winter training in endurance sport athletes Exerc Immunol Rev. 2013

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes J Sports Sci. 2016

A systems-based investigation into vitamin D and skeletal muscle repair, regeneration, and hypertrophy American Journal of Physiology 2015

The influence of winter vitamin D supplementation on muscle function and injury occurrence in elite ballet dancers: A controlled study Journal of Science and Medicine in Sport 2014

Vitamin D status in professional ballet dancers: Winter vs. summer J Science and Medicine in Sport 2013

Health, Hormones and Human Performance Part 2

Endocrine and Metabolic aspects of Sports and Exercise Medicine are crucial determinants of health and human performance, from reluctant exerciser through to elite athlete and professional dancer. This is what the recent BASEM spring conference set out to demonstrate. The previous blog described functional disruption of Endocrine networks caused by non-integrated periodisation of the three key lifestyle factors of exercise/training, nutrition and recovery/sleep, can lead to adverse effects on health and athletic performance.

Slide1
Integrated periodisation of exercise, nutrition, recovery for optimisation of health and performance (Keay BJSM 2017)

Grace, aesthetic line and ethereal quality belie the athletic prowess required in ballet. What are the Endocrine, metabolic and bone health consequences for this unique group of athletes? Dr Roger Wolman (Medical Advisor to National Institute for Dance Medicine and Science) returned to the important topic of insufficient energy availability in sport/dance where being lightweight confers a performance advantage, resulting in dysfunction in multiple endocrine axes. Dr Wolman discussed his recent research studies in dancers revealing an intriguing synergistic action between oestrogen and vitamin D, which is itself a steroid hormone. Evidence was presented to demonstrate how being replete in vitamin D has beneficial effects on bone, immunity and muscle function. Thus it is key in preventing injury and supporting health in athletes, with particular relevance in premenarchal and postmenopausal women, who are in relative oestrogen deficient states. This presentation will certainly change my clinical practice and, I am sure, that of many in the audience, in ensuring that athletes/patients are vitamin D replete. This may have to be achieved in the form of strategic use of sports informed vitamin D supplementation, given that even walking naked for 5 hours a day outside during UK winter, would not stimulate enough vitamin D production. Therefore, to the relief of many in the audience, Dr Wolman did not recommend this strategy.

Dr Kate Ackerman (member of RED-S IOC working group) explained why we should all tap into our inner endocrinologist. Sport and Exercise Medicine (SEM) goes far beyond diagnosing and treating injury. Is there any underlying endocrine cause for suboptimal health, performance or injury? Be this an endocrine diagnosis that should not be missed, or a functional endocrine dysfunction due to relative energy deficiency in sports (RED-S). Dr Ackerman explained the importance of the multidisciplinary team in both identifying and supporting an athlete experiencing the consequences of RED-S. New research from Dr Ackerman’s group was presented indicating the effects of RED-S on both health and athletic performance.

Females now have combative roles alongside their male counterparts. What are the implications of this type of intensive exercise training? Dr Julie Greaves (Research Director of the ministerial women in ground close combat research programme) presented insightful research revealing that differences in the geometry of bone in men and women can predispose towards bone stress injury and account for increased incidence in this type of injury in female recruits.

Lunchtime discussion and debate was focused on the determinants of athletic gender, lead by Dr Joanna Harper and Professor Yannis Pitsiladis (International Federation of Sports Medicine). Rather than relying on genetic sex, testosterone concentration was proposed as the criteria for determining whether an athlete competes in male or female events. That testosterone concentration is linked to performance was demonstrated in a study published last year in the BMJ where female athletes in the upper tertile of testosterone were shown to have a performance advantage in certain strength based track and field disciplines. This could potentially be an objective, functional metric used to determine sporting categories for transgender and intersex athletes. The only current uncertainty is how previously high levels of testosterone seen in male, or intersex athletes would have already had an impact on physiology, if this athlete then wished to compete as female and therefore lower testosterone levels with medication.

Nutrition is a key component in optimising health and performance through the Endocrine system. Dr Sophie Killer (English Institute of Sport) explained practical implications for athletes. In a study stimulating a training camp, there were distinct differences between athletes on different regimes of carbohydrate intake in terms of endocrine markers and psychological effects. Those athletes on restricted carbohydrate intake fared worse.

Insulin insensitivity is the underlying pathological process in developing type 2 diabetes mellitus (T2DM) and metabolic syndrome. What is the crucial lifestyle intervention to combat this? Dr Richard Bracken (Swansea University) presented the science behind why and how exercise improves blood glucose control and therefore ultimately risk of developing the macro and microvascular complications of diabetes. T2DM is an increasing health issue in the population, which has to be addressed beyond reaching for the prescription pad for medication. Dr Bracken outlined some effective strategies to encourage the reluctant exerciser to become more active. Having worked myself in NHS diabetic clinics over many years, this was a key presentation at the conference to demonstrate that SEM goes far beyond a relatively small group of elite athletes. Highlighting the crucial role of physical activity in supporting health and performance through optimisation of endocrine networks: uniting the elite athlete and the reluctant exerciser.

One road to Rome
One Road to Rome (BJSM Keay 2017)

Motivate2Move initiative aims to shift the emphasis from treating disease, to preventing disease. Dr Brian Johnson presented the excellent resource for healthcare professionals to encourage, motivate and educate patients in order to consider exercise as an effective and enjoyable way to improve health.

Hormones play a key role in health and human performance, applicable to all levels of exerciser from reluctant exerciser to elite athlete.

FactorsWordCloud4

References

Health, Hormones and Human Performance BASEM Spring Conference

Video of presentation on Endocrine and Metabolic aspects of Sport and Exercise Medicine from BASEM Spring Conference

Sports Endocrinology – what does it have to do with performance? Keay BJSM 2017

Lifestyle Choices for optimising health: exercise, nutrition, sleep Keay BJSM 2017

One road to Rome: Exercise Keay, BJSM 2017

 

 

Healthy Hormones

Is your training in tune with your hormones and nutrition to optimise your athletic performance?

Hormones are internal chemical messengers regulating all aspects of your health and athletic performance. Discussed at recent BASEM conference “Health Hormones and Human Performance”

webmd_rm_photo_of_porous_bones
Bone health can be at risk if hormone status not optimal

How? To enable your hormones to do the best job they can for your health and sport performance, you need to find a balance between what, how much and when you train, eat and sleep. In the diagram below, this represents staying on the healthy green plateau. Too much, or too little of any of these choices can lead to imbalances and tipping off the green plateau into the red, less healthy peripheries.

Slide1
Integrated periodisation of training, nutrition and recovery for optimal health and performance (Keay, BJSM 2017)

What? Imbalances between training load, nutrition and recovery can cause problems in the Endocrine system: the whole network of hormone interactions throughout your body. The bottom line is that if insufficient energy is provided through nutrition to cover both your training demands and the “housekeeping” activities within the body to keep you alive, then your body goes into energy saving mode. This situation is called relative energy deficiency in sports (RED-S) and has the potential to adversely impact one or more of the important systems in your body vital for optimal health and performance.

RED-S has evolved from the female athlete triad described in 1980s by Barbara Drinkwater in NEJM, where although female runners were consuming same dietary intake, those with higher training load were more likely to have menstrual dysfunction and low bone mineral density. Since this original description it has become obvious that the reproductive axis is just one of several hormone networks to be impacted by low energy availability and that RED-S also impacts the other half of the population: men.

red-s
Potential Multisystem effects of RED-S (IOC statement BJSM 2014)

Why? Suboptimal levels of energy availability to support health and performance can arise unintentionally, for example with increased training loads and/or times of growth and development in young athletes. Intentionally restrictive eating patterns can also be the cause of RED-S, particularly in sports/dance where low body weight confers a performance or aesthetic advantage. It is an indisputable fact that in order cycle up a mountain you need to overcome gravity and produce high watts/kg. Equally it is pretty impossible to do pointe work, let alone 32 fouttées en tournant en pointe unless you are a lightweight dancer. However if this at the expense of disrupting your hormones, then the advantage of being low body weight will be lost.

How to know? How to know if you, a teammate or a fellow athlete is at risk of RED-S? If you are a female athlete then your hormones are in balance if you are having regular periods (this does not include withdrawal bleeds as result of being on the oral contraceptive pill). Any woman of reproductive age from 16 years to the menopause should have regular periods (unless pregnant). Regular menstruation acts as the barometer of healthy hormones in women. If this is not the case, whether you are an athlete or not, you need to get this checked out medically to exclude underlying medical conditions. Having excluded these, then you need to review the integrated periodisation of training, nutrition and recovery. In male athletes there is not such an obvious sign that your hormones are at healthy levels. However recurrent injury/illness/fatigue can be warning signs. The diagram below shows all the potential adverse effects of RED-S on performance. Be aware that you do not have to have all, or indeed be aware of any of these effects if you develop RED-S.

Screen Shot 2017-05-20 at 19.16.28
Potential Performance effects of RED-S (IOC statement BJSM 2014)

So What? If you are an athlete/dancer, you may be thinking that none of this applies to you. You are feeling and performing fine. Maybe you have not yet experienced any of the detrimental effects of RED-S. However, you will never know how good an athlete you could be and whether you truly are performing to your full potential unless you put yourself in the best position in terms of your hormones to achieve this goal.

performance-potential
Suboptimal performance as result of RED-S (Keay, BJSM 2017)

Key Points

• Insufficient nutrition intake (quantity and quality), whether intentional or not, results in RED-S and multiple hormonal disruptions

• RED-S has detrimental health and athletic performance consequences in both the short and the long term

• Some consequences of RED-S are irreversible for example poor bone health, unless intervention is swift

Check points

• Are you suffering with frequent injuries/fatigue/illness over last 3 months or more?

• Female athletes: if 16 years or older have your periods not started? Have you missed more than 3 consecutive periods?

If yes to any of above, seek medical advice from someone with experience Sports Endocrinology. Now! The longer you leave the situation the harder it will be to rectify. Initially underlying Endocrine conditions per se have to be ruled out. RED-S is a functional dysfunction of the Endocrine system, so a diagnosis of exclusion. Having established RED-S as the diagnosis, monitoring Endocrine markers can be very helpful as these are examples of objective metrics in monitoring energy availability and therefore response to optimising integrated periodisation of nutrition, training and recovery.

Slide1
Integrated periodisation of key training factors support healthy hormones to drive improvements in performance

What to do? Don’t ignore! Although you may think you are fine, if your hormones are not working for you, then you will never reach your full potential as an athlete/dancer. For female athletes having regular periods means your hormones are in healthy ranges and this is normal. Not starting and/or missing periods is not healthy, for any woman.

For both male and female athletes, if you are experiencing recurrent injury, fatigue or illness, you need to get this checked out. There may be a simple explanation such as viral infection, low vitamin D or iron. However it may be that the underlying reason is due to hormone issues.

If you are an athlete, coach, teacher or parent and concerned that you/an athlete in your care has not got the balance right to optimise health and athletic performance, then a 3 way discussion will help and support the decision to seek medical advice as appropriate.

References

Lifestyle Choices for optimising health: exercise, nutrition, sleep Keay, BJSM 2017

Optimal health: including female athletes! Part 1 BJSM 2017

Optimal health: including male athletes! Part 2 BJSM 2017

Optimal Health: Especially Young Athletes! Part 3 BASEM 2017

Optimal Health: For All Athletes! Part 4 BASEM 2017

Low Energy Availability is Difficult to Assess But Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes Sport Nutrition and exercise Metabolism 2017

Cumulative Endocrine Dysfunction in Relative Energy Deficiency in Sport (RED-S) BJSM 2018

Presentation at BASEM conference “Health, Hormones and Human Performance”

 

Health, Hormones and Human Performance Part 1

How hormones determine health and athletic performance

Endocrine and Metabolic aspects of Sports and Exercise Medicine are crucial determinants of health and human performance, from reluctant exerciser through to elite athlete and professional dancer. This is what I set out to demonstrate as the chair of the recent British Association of Sport and Medicine conference, with insightful presentations from my colleagues whom I had invited to share their research and practical applications of their work. The audience comprised of doctors with interest in sport and exercise medicine, representatives from the dance world, research scientists, nutritionists, physiotherapists, coaches and trainers. In short, all were members of multi-disciplinary teams supporting aspiring athletes. The importance of the conference was reflected in CDP awards from FSEM, BASES, Royal College of Physicians (RCP), REP-S and endorsement for international education from BJSM and National Institute of Dance Medicine and Science (NIDMS).

Exercise is a crucial lifestyle factor in determining health and disease. Yet we see an increasing polarisation in the amount of exercise taken across the general population. At one end of the spectrum, the increasing training loads of elite athletes and professional dancers push the levels of human performance to greater heights. On the other side of the spectrum, rising levels of inactivity, in large swathes of the population, increase the risk of poor health and developing disease states. Which fundamental biological processes and systems link these groups with apparently dichotomous levels of exercise? What determines the outcome of the underlying Endocrine and metabolic network interactions? How can an understanding of these factors help prevent sports injuries and lead to more effective rehabilitation? How can we employ Endocrine markers to predict and provide guidance towards beneficial outcomes for health and human performance?

If you weren’t able to come and participate in the discussion, these are some topics presented. My opening presentation (see video below) set the scene, outlining why having an optimally functioning Endocrine system is fundamental to health and performance. Conversely, functional disruption of Endocrine networks occurs with non integrated periodisation of the three key lifestyle factors of exercise/training, nutrition and recovery/sleep, which can lead to adverse effects on health and athletic performance.

In the case of an imbalance in training load and nutrition, this can manifest as the female athlete triad, which has now evolved into relative energy deficiency in sports (RED-S) in recognition of the fact that Endocrine feedback loops are disrupted across many hormonal axes, not just the reproductive axis. And, significantly, acknowledging the fact that males athletes can also be impacted by insufficient energy availability to meet both training and “housekeeping” energy requirements. Why and how RED-S can affect male athletes, in particular male competitive road cyclists, was discussed, highlighting the need for further research to investigate practical and effective strategies to optimise health and therefore ultimately performance in competition.

A degree of overlap and interplay exists between RED-S (imbalance in nutrition and training load), non functional over-reaching and over-training syndrome (imbalances in training load and recovery). Indeed research evidence was presented suggesting that RED-S increases the risk of developing over-training syndrome. In these situations of functional disruption of the Endocrine networks, underlying Endocrine conditions per se should be excluded. Case studies demonstrated this principle in the diagnosis of RED-S. This is particularly important in the investigation of amenorrhoea. All women of reproductive age, whether athletes or not, should have regular menstruation (apart from when pregnant!), as a barometer of healthy hormones. Indeed, since hormones are essential to drive positive adaptations to exercise, healthy hormones are key in attaining full athletic potential in any athlete/dancer, whether male or female. Evidence was presented from research studies for the role of validated Endocrine markers and clinical menstrual status in females as objective and quantifiable measures of energy availability and hence injury risk in both male and female athletes.

Slide1
Triumvirate of external factors impacting Endocrine system and hence performance

Alongside training metrics, if female athletes recorded menstrual pattern (as Gwen Jorgensen recently showed on her Training Peaks) and all athletes kept a biological passport of selected Endocrine markers; this could potentially identify at an early stage any imbalances in the triumvirate of training load, nutrition and recovery. Pre-empting development of RED-S or over-training syndrome, supports the maintenance of healthy hormones and hence optimal human performance.

Look out for presentations from speakers which will be uploaded on BASEM website shortly.

References

Video of presentation on the Endocrine and Metabolic Aspects of Sports and Exercise Medicine BASEM conference “Health, Hormones and Human Performance”

Study of hormones, body composition, bone mineral density and performance in competitive male road cyclists Investigation of effective and practical nutrition and off bike exercise interventions

Sports Endocrinology – what does it have to do with performance? Keay BJSM 2017

 

 

 

Cyclists: How to Support Bone Health?

Screen Shot 2018-02-25 at 16.51.20.png
Supporting Bone Health

The wonderfully named “hip hop” study was conducted to investigate whether hopping would improve the strength of the hip bone in older males. You may be wondering how this is relevant to male cyclists in their twenties. Yet, in a recent pilot study, some male cyclists were found to have areas of the skeleton that were below average bone mineral mineral (BMD) for an 85 year old man. This finding of low BMD in cyclists was confirmed in a recent BBC programme where Dr Karen Hind at Leeds Beckett University presented the differences in BMD across sports. Keen-eyed cyclists amongst you will have recognised Ed Clancy from JLT Condor representing cyclists, though these findings will be relevant to all levels of competitive cyclists.

So maybe research with the same aims as the “hip hop” study is exactly what needs to be conducted amongst male cyclists to investigate practical and effective ways of supporting bone health and ultimately preventing injury and optimising performance. This is aim of forthcoming research in collaboration with Dr Hind.

webmd_rm_photo_of_porous_bones
Microscopic structure of bone

In common with other sports, cycling is an excellent form of exercise, driving positive adaptations throughout the body, such as improved cardiovascular fitness, body composition, muscular strength and endurance together with beneficial psychological effects. However, unlike many other forms of exercise, cycling does not encourage beneficial adaptations to the full skeletal system. This is due to a lack of mechanical osteogenic (bone building) stimuli provided in cycling, particularly at the lumbar spine. In competitive road cycling, low body mass confers a performance advantage, so restrictive or inconsistent nutrition can lead to relative energy deficiency in sport (RED-S). The consequent Endocrine system dysfunction can compound the negative effects on bone health of a non-load-bearing sport.

In a study of masters cyclists, decreases in BMD at all sites were more marked than in sedentary individuals. Some cyclists went from being osteopenic to osteoporotic; a rare case where exercise has a negative impact on a system in the body. Does this matter? Like all athletes, cyclists are more concerned with current athletic performance than warnings about future issues, such as osteoporosis and fracture. Yet, out of athletes across all sports, cyclists should perhaps be the most concerned. In the case of runners, suboptimal bone heath and associated RED-S may well present as a stress fracture. In the case of cyclists by the nature of non-load bearing exercise, they can push for longer with suboptimal bone and nutritional status. The full extent of any bone health issues may only come to light as result of a bike crash. Looking at the time off from injury in elite cyclists, the majority are due to fracture, with vertebral fractures often requiring long duration of recovery compared to other sites.

Maybe maintenance of BMD for adult cyclists would be realistic goal. How can this be achieved?

Multidirectional, dynamic loading patterns have been shown to produce the most positive skeletal responses. This is seen in the different site specific effects of sports, where changes of direction or plane of movement provide maximal mechanical osteogenic stimulus. Jumping and hopping have been shown to be good for bone health in premenopausal women, where brief high impact exercises were found to be beneficial for the bone mineral density (BMD) of the femoral neck of the hip.

What about targeting the lumbar spine, which is the site most at risk in cyclists? In young children, a few mechanical loading cycles of two-footed jumping from a small step improved BMD at lumbar spine compared with those that did not perform this jumping exercise. However bone is at its most responsive in childhood and skeletal loading has a more long term effect on both microarchitecture and BMD than when performed as an adult. Nevertheless, even in adulthood bone is still a dynamic tissue, able to adapt to loading stresses. Resistance training seems to be the most effective way of providing mechanical osteogenic stimulus to the lumbar spine with an additional indirect osteogenic effect of muscle pulling on bone. For example rowers have site-specific increases in BMD at the lumbar spine. In a recent study, resistance training was found to improve BMD in male distance runners with similar levels of testosterone and bone markers. This concurs with recent pilot study of cyclists, where those performing current resistance training or with recent history of participating in other sports, such as rugby or rowing, fared better in terms of BMD. In other words, the improvement in BMD mediated via mechanical rather than Endocrine effects.

Nevertheless, any form of skeletal-loading exercise will not produce the expected beneficial osteogenic effect, if performed in suboptimal nutritional status. Sufficient quantity and quality of nutrition are required to prevent RED-S. Specific nutritional factors, such as vitamin D, calcium and polyphenols, are recognised to be important in bone health. Boron is also described as decreasing bone resorption by stabilising and extending the half-life of vitamin D and improving sex steroid availability. Whilst high intake of caffeine, which can accumulate if athletes take on board caffeine gels, has a negative impact on BMD. Optimal nutritional status will in turn support the Endocrine system to mediate advantageous adaptations to exercise exercise, including bone health.

How can cyclists optimise bone health and performance on the bike with consistent and targeted skeletal-loading exercise and nutritional strategies? Watch this space! A study is planned to investigate practical and effective strategies to achieve this. No on bike hip hop dance required.

In meantime there will be more discussion on “Health, Hormones and Human Performance” at the BASEM conference 22 March. All welcome, including athletes and coaches, alongside healthcare professional working with athletes.

References

Male Athletes: the Bare Bones of Cyclists

Cyclists: Make No Bones About It BJSM 2018

Which type of exercise gives you the strongest bones? BBC

Studies

Male Cyclists: Bones, Body composition, Nutrition, Performance BJSM 2018

Longitudinal Changes in Bone Mineral Density in Male Master Cyclists and Nonathletes The Journal of Strength & Conditioning Research 2011

A meta-analysis of brief high-impact exercises for enhancing bone health in premenopausal women  Osteoporosis International 2012

Jumping Improves Hip and Lumbar Spine Bone Mass in Prepubescent Children: A Randomized Controlled Trial JBMR 2001

Review Exercise and Sports Science Australia (ESSA) position statement on exercise prescription for the prevention and management of osteoporosis Journal of Science and Medicine in Sport 2016

Resistance training is associated with higher bone mineral density among young adult male distance runners independent of physiological factors The Journal of Strength & Conditioning Research 2018

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

Nothing Boring About Boron Integrated Medicine 2015

Cumulative Endocrine Dysfunction in Relative Energy Deficiency in Sport (RED-S) BJSM 2018

Cyclists: Make No Bones About It

Competitive cyclists are potentially at risk of suboptimal bone health. Although cycling is excellent for cardiovascular fitness, this type of non skeletal loading exercise does not mechanically stimulate osteogenesis (bone formation). This situation of low mechanical osteogenic stimulus to build bone can be compounded by restrictive eating patterns and associated hormone dysfunction of relative energy deficiency in sports (RED-S).

In a recent pilot study 7/10 competitive cyclists (Cat 2 and above) had low age-matched bone mineral density (BMD) in the lumbar spine. This is comparable to another study where 15/28 male cyclists training over eight hours a week were found to have low BMD for their age and were therefore at risk of low trauma fracture. However, cyclists with a lower training volume (Cat 4) did not fair so badly in terms of BMD, due to higher body mass index (BMI) and fat mass. Although greater body mass mechanically loads the skeleton, the downside is that you need to generate more power to get up a hill.

Why is cycling unique compared to other sports where an important adaptation to training is to improve, not impair, bone health? What are the practical solutions to prevent this potential negative effect of cycle training?

fullsizeoutput_2b8
Site Specific Effects on Bone Mineral Density

The illustration shows how different sports exert site specific effects on the bone mineral density of the skeleton. In general terms, hip femoral neck BMD is more dependent on mechanical loading osteogenic stimuli, whereas lumbar spine BMD is more dependent on nutritional and Endocrine status.

What are the most effective mechanical osteogenic stimuli? Evidence from animal models demonstrates that bone responds to exercise that is dynamic, non-repetitive and unpredictable. Load and repetitions are not such important factors. This is shown in a study of track and field athletes, where sprinters were found to have higher BMD at load bearing sites of the skeleton than long distance runners due to a local loading effect rather than a systemic effect associated with repetitive loading nature of longer distance running. The other important consideration is that sprinters and rugby players tend to weigh more with higher lean mass than distance runners, providing higher skeletal loading forces. These differences in anthropometric and body composition metrics are also associated with different nutritional and Endocrine status.

In contrast to sports involving running, rowing creates a mechanical osteogenic stimulus that is directed through the lumbar spine, resulting in an associated increase in BMD at this site. This site specific effect of rowing can prevent bone loss at the lumbar that would be anticipated with rowers experiencing RED-S.

Swimming and cycling are similar in that both these types of exercise do not provide mechanical skeletal loading osteogenic stimulus. However the consequences on BMD, particularly at the lumbar spine, can be compounded in cycling by the performance advantage of low body mass and therefore potential of restrictive nutrition and consequent effect on Endocrine status: factors which impact bone health.

In the recent pilot study of competitive cyclists, although 7/10 had below average for age lumbar spine BMD, those with stronger bones had a previous history of other sports that improve BMD at this site: namely rugby and rowing, together with the cyclist doing concurrent and consistent weight training throughout the season. These findings were consistent with a study where male riders who had undertaken pre-season weight training had better BMD than riders who had not. Cumulative skeletal loading over a lifetime determines BMD. However, the skeletal system is dynamic and as with any training adaptation, any beneficial effects of skeletal loading exercise are reversible if not maintained throughout the lifespan.

Typically, the objective of off-bike strength and conditioning (S&C) is aimed at producing higher watts on the bike. Some strengthening exercises may, as by product, produce an osteogenic stimulus indirectly by muscle pulling on bone. Should off-bike work include specific mechanical axial skeletal loading exercises that are continued throughout the season? Skeletal loading exercises for cyclists would have to be effective and practical, not requiring access to gym and possible to fit into training schedule throughout the season. This will be investigated in an forthcoming study of competitive male cyclists.

In meantime there will be more discussion on “Health, Hormones and Human Performance” at the BASEM conference 22 March. All welcome, including athletes and coaches, alongside healthcare professional working with athletes.

References

Male Cyclists: bones, body composition, nutrition, performance

Cycling and bone health: a systematic review BMC Medicine 2012

Male Athletes: the Bare Bones of Cyclists

Comparisons of Bone Mineral Density Between Recreational and Trained Male Road Cyclists Clinical Journal of Sport Medicine 2016

Longitudinal Assessment of Bone Mineral Density and Body Composition in Competitive Cyclists Journal of Strength and Conditioning Research 2017

Kings and Queens of the Mountains Science4Perforamnce

Inhibition of osteopenia by low magnitude, high-frequency mechanical stimuli Drug Discovery Today 2001

Bone density and neuromuscular function in older competitive athletes depend on running distance Osteoporosis International 2012

Menstrual state and exercise as determinants of spinal trabecular bone density in female athletes BMJ 1990

Male Athletes: the Bare Bones of Cyclists

Resistance Training Is Associated With Higher Lumbar Spine and Hip Bone Mineral Density in Competitive Male Cyclists Journal of Strength and Conditioning Research 2018

A meta-analysis of brief high-impact exercises for enhancing bone health in premenopausal women  Osteoporosis International 2012

Jumping Improves Hip and Lumbar Spine Bone Mass in Prepubescent Children: A Randomized Controlled Trial JBMR 2001

Longitudinal Changes in Bone Mineral Density in Male Master Cyclists and Nonathletes The Journal of Strength & Conditioning Research 2011