Tag: sport performance

Hormones and Sports Performance

15 July 2017

WADA

The interactive network effects of the Endocrine system are key in producing effective adaptations to exercise. This in turn results in improved sport performance. Athletes are aware of the crucial role of the Endocrine system in sports performance. Therefore it is not surprising that, on the World Anti-Doping agency (WADA) banned list, the majority of prohibited substances both in and out of competition are hormones, mimetics and hormone and metabolic modulators. In 2013 hormones accounted for 75% of all adverse analytical findings. Use of such substances to enhance performance is not only illegal and against the spirit of sport, but also potentially harmful to the health of the athlete.

Considering some of these prohibited hormones, the usual suspects start with anabolic agents: anabolic androgenic steroids whether these be synthetic derivatives taken exogenously or molecular identical endogenous steroids, including metabolites and isomers, administered exogenously.  In a study recently published in the BJSM, female athletes with free testosterone levels in the highest tertile displayed better performance than those in lowest tertile of up to 4.5% in certain power/anaerobic events such as 400m, 800m, hammer and pole jump. This may be due to associated body composition with increased lean mass and “risk taking” behaviour. In 2015, the Court of Arbitration for Sport ruled that the IAAF should suspend the existing upper limit on female athlete testosterone, of 10nmol/l, because at the time there was insufficient evidence that such levels would improve performance in female athletes. In view of the results of this study, the situation may have to be reviewed. This is clearly an ethical dilemma regarding intersex athletes, whose hyerandrogenism is due to endogenous biological factors.

Next up there are peptide hormones/growth factors/mimetics. As previously discussed, growth hormone (GH) proved a challenging peptide hormone for which to develop a dope test. Firstly what are the “normal” ranges for elites athletes, seeing as exercise and sleep are the two major stimuli for GH release? Furthermore, elite athletes represent a subset of the population, for whom the normal range may differ. Secondly exogenous genetically engineered GH is to all intents and purposes identical to endogenous secreted GH, with a relatively short half life. Hence early on in development of a dope test we realised that downstream markers, particularly of bone turnover would have to be used. This brings the discussion to erythropoietin (EPO). In a similar way to GH and allied releasing factors, increases in key surrogate variables producing performance enhancement are measured. In the case of exogenous EPO these are changes in haemoglobin and haematocrit as recorded in an athletes’ biological passport. A recent study on amateur cyclists given EPO in a double blind randomised placebo controlled trial, reported no improvement in a submaximal field test. Although the effects in elite cyclists would arguably be more relevant, this is not possible for obvious ethical reasons. Nevertheless the effects on elite cyclists during maximal efforts, for example in an attack on a mountainous stage in the Tour de France, would not necessarily correlate to amateurs in submaximal conditions, where there may be other limiting factors to performance. In addition athletes may use supraphysiological dosing regimens (“stacking” or “pyramiding”), not necessarily comparable to those used in clinical studies. In my opinion, apart from potential ergogenic benefits, whatever the degree, the intention to “take a short cut” to improve performance is the issue, not to mention the adverse health sequelae, for example, the study noted a thrombotic tendency with EPO, even in modest doses.

Hormone and metabolic modulators have received attention following the fall from grace of Maria Sharapova. Meldonium which is licensed for use in Baltic countries has beneficial anti-ischaemic effects in cardiovascular, neurological and metabolic disease states. Apparently this drug was use amongst Soviet troops during the war in mountainous Afghanistan. Amongst athletes the intended purpose is to improve endurance exercise performance and recovery post exercise. This is an example where an unfortunate spin off from developing drugs to treat disease states, is that such drugs are also see by some athletes as a short cut to enhance sport performance.

Although thyroxine is not on the banned list, there are certainly arguments that exogenous thyroxine should not be given to athletes, unless there is definitive biochemical evidence that the athlete suffers with hypothyroidism: as defined by criteria for diagnosing this condition with consistently elevated thyroid stimulating hormone (TSH) above the normal range, with paired low T4. Thyroid autoantibodies may also provide extra clinical information. The effect of intense training on the hypothalamic-pituitary-thyroid axis is to slightly suppress both TSH and T4, whilst these remain in the normal range. In this instance medicating with exogenous thyroxine would be to support recovery from training, rather than to legitimately treat a proven medical condition. In a similar way a TUE is only justified for testosterone in pathological disorders of the hypothalamo-pituitary-testicular axis and not for suppressed testosterone as a result of training stress.

Unfortunately supplements are a source of preventable anti-doping rule violations (ADRV) representing up to half of the total ADRVs. Either such supplements have not listed all the contents, or contamination has occurred during manufacture. If an athlete wishes to take supplements, certainly it is advisable only to take reliably tested products. Nevertheless even if an athlete unintentionally ingests prohibited substances, then ultimately they are still liable. If claims of the benefits of such supplements sound too good to be true, they probably are. Ultimately supplements will not win races and there is no substitute for periodised training, nutrition and recovery.

Effectively there is an arms race between would-be doper and medical expertise in Sports Endocrinology. However, freezing samples for potential re-analysis with emerging understanding and technology in the future is an added deterrent for athletes whose intention is to take a short cut to improving sport performance.

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

Endocrine system: balance and interplay in response to exercise training

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

Enhancing Sport Performance: Part 1 Dr N. Keay, British Association of Sport and Exercise Medicine 2017

Keay N, Logobardi S, Ehrnborg C, Cittadini A, Rosen T, Healy ML, Dall R, Bassett E, Pentecost C, Powrie J, Boroujerdi M, Jorgensen JOL, Sacca L. Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential as a marker of GH abuse in sport: a double blind, placebo controlled study. Journal of Clinical Endocrinology and Metabolism. 85 (4) 1505-1512. 2000.

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

Enabling Sport Performance: part 2

Enhancing Sports Performance: part 3

World Anti-Doping Agency

Serum androgen levels and their relation to performance in track and field: mass spectrometry results from 2127 observations in male and female elite athletes British Journal of Sports Medicine

Doping Status of DHEA Treatment for Female Athletes with Adrenal Insufficiency Clinical Journal of Sports Medicine 2017

Testosterone treatment and risk of venous thromboembolism: population based case-control study British Medical Journal 2016

Effects of erythropoietin on cycling performance of well trained cyclists: a double-blind, randomised, placebo-controlled trial The Lancet, Haematology 2017

Meldonium use by athletes at the Baku 2015 European Games. Adding data to Ms Maria Sharapova’s failed drug test case British Journal of Sports Medicine 2016

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

Australian Sport Anti-Doping Authority

 

Fatigue, Sport Performance and Hormones…

2 May 2017

How do you feel on Monday morning, when the alarm wakes you at 7am with a day of work ahead after the weekend? A bit tired, slightly lethargic, sluggish, maybe a little bit down, perhaps a few regrets about somewhat too much alcohol/food over weekend, frustrated that the exercise training schedule didn’t go according to plan?sleep

There are many causes of fatigue and sport underperformance: Endocrine, immunological, infective, metabolic, haematological, nutritional, digestive, neoplastic….. The adrenal gland in the Endocrine system in particular has come in for some bad press recently.

Adrenal woes

Undoubtedly the adrenal glands have a case to answer. Situated above the kidneys these Endocrine glands produce glucocorticoids, mineralocorticoids, androgens from the adrenal cortex and from the adrenal medulla adrenaline. Glucocorticoids (e.g. cortisol) have a metabolic function to maintain energy homeostasis and an immune function to suppress inflammation. Mineralocorticoids (e.g. aldosterone) maintain electrolyte and water balance. As mineralocorticoids and glucocorticoids are similar biological steroid molecules, there is some degree of overlap in their actions.

Addison’s disease and Cushing’s disease are serious medical conditions, corresponding respectively to under or over production by the adrenal glands of steroid hormones. Someone presenting in Addisonian crisis is a medical emergency requiring resuscitation with intravenous hydrocortisone and fluids. Conversely those with Cushing’s can present with hypertension and elevated blood glucose. Yet, apart from in the extremes of these disease states, cortisol metrics do not correlate with clinical symptoms. This is one reason why it is unwise and potentially dangerous to stimulate cortisol production based on clinical symptoms. Inappropriate exogenous steroid intake can suppress normal endogenous production and reduce the ability to respond normally to “stress” situations, such as infection. This is why the prescription of steroids, for example to reduce inflammation in autoimmune disease, is always given in a course of reducing dose and a steroid alert card has to be carried. Athletes should also be aware that exogenous steroid intake is a doping offence.

However, what is the “normal” concentration for cortisol? Well, for a start, it depends what time of day a sample is taken, as cortisol is produced in a circadian rhythm, with highest values in the morning on waking and lowest levels about 2/3am. Nor is this temporal periodicity of production the only variable, there are considerations such as tissue responsiveness and metabolism (break down) of the hormone. On top of these variables there are other inputs to the feedback control mechanism, which can in turn influence these variables. In other words, focusing on the steroid hormone production of the adrenal gland in isolation, could overlook underlying hypothamalmic-pituitary-adrenal (H-P-A) axis dysfunction and indeed wider issues.

Much maligned thyroid

That is not end of the possible causes of fatigue and sport underperformance: the H-P-A axis is just one of many interrelated, interacting Endocrine systems. There are many neuroendocrine inputs to the hypothalamus, the gate keeper of the control of the Endocrine system. Furthermore there are network interaction effects between the various Endocrine control feedback loops. For example cortisol towards the top end of “normal” range can impede the conversion at the tissue level of thyroxine (T4) to the more active triiodothyronine (T3) by enzymes which require selenium to function. Rather T4 can be converted to reverse T3 which is biologically inactive, but blocks the receptors for T3 and thus impair its action. This in turn can interfere with the feedback loop controlling thyroid function (hypothalamic-pituitary-thyroid axis). The physiological ratio of T4 to T3 is 14:1, which is why supplementation with desiccated thyroid is not advisable with ratio of 4:1. There are other processes which can crucially interfere with this peripheral conversion of T4 to T3, such as inflammation and gut dysbiosis, which can occur as result of strenuous exercise training. So what might appear to be a primary thyroid dysfunction can have an apparently unrelated underlying cause. Indeed amongst highly trained athletes thyroid function can show an unusual pattern, with both thyroid stimulating hormone (TSH) and T4 at low end of the “normal “range, thought to be due to resetting of the hypothalamic-pituitary control signalling system. This highlights that the “normal” range for many hormones comprises subsets of the population and in the case of TSH, the “normal” range is not age adjusted, despite TSH increasing with age. As described by Dr Boelaert at recent conferences, there is certainly no medical justification for reports of some athletes in the USA being given thyroxine with TSH>2 (when the normal range is 0.5-5mU/l). Although thyroxine is not on the banned list for athletes, it could have potentially serious implications for health due to its impact on the Endocrine system as a whole.

Endocrine system interactions

SportsEndocrinologyWordCloud

Symptoms of fatigue are common to many clinical conditions, not just dysfunction in an Endocrine control axis in isolation, nor even the network interactive effects of the Endocrine system in isolation. For example, the impact of nutrition relative to training load produces a spectrum of clinical pictures and Endocrine disturbances seen in Relative Energy Deficiency in Sport (RED-S) in terms of health and sport performance.

Underlying mechanisms of Endocrine dysfunction

There may be predisposing factors in developing any clinical syndrome, the usual suspects being inflammation: whether infective, dysbioses, autoimmune; nutritional status linked with endocrine status;  training load with inadequate periodised recovery to name a few….

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

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

Sports Endocrinology – what does it have to do with performance? British Journal of Sport Medicine 2017

Advanced Medicine Conference, Royal College of Physicians, London 13-16 February 2017, Endocrine session: Dr Kristien Boelaert, Dr Helen Simpson, Professor Rebecca Reynolds

Subclinical hypothydroidism in athletes. Lecture by Dr Kristeien Boelaert, British Association of Sport and Exercise Medicine Spring Conference 2014. The Fatigued Athlete

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

Relative Energy Deficiency in Sport CPD module British Association of Sport and Exercise Medicine 2017

Sleep for health and sports performance British Journal of Sport Medicine 2017

Inflammation: why and how much? British Association of Sport and Exercise Medicine 2017

Clusters of athletes British Association of Sport and Exercise Medicine 2017

Enhancing Sport Performance: Part 1 British Association of Sport and Exercise Medicine 2017

Balance of recovery and adaptation for sports performance British Association of Sport and Exercise Medicine 2017

Annual Sport and Exercise Medicine Conference, London 8/3/17 Gut Dysbiosis, Dr Ese Stacey

Adrenal fatigue does not exist: a systematic review BMC Endocrine Disorders. 2016; 16(1): 48.

A Controversy Continues: Combination Treatment for Hypothyroidism Endocrine News, Endocrine Society April 2017

Sport Performance and Relative Energy Deficiency in Sport

11 March 2017

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.

From population based norms to personalised medicine: Health, Fitness, Sports Performance

28 December 2016

animation

“Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. World Health Organisation 1948

There has been criticism of this definition, arguing that the word “complete” has opened the door to today’s more medicalised society. However, this trend coincides with increased volume of “patients” seeking optimal health, together with doctors who have a more extensive repertoire of medical interventions at their disposal. In a time-pressed society there is less opportunity for either patient or doctor to explore longer term adaptive measures and prevention strategies, which facilitate taking responsibility for your health. Fortunately Sport and Exercise Medicine became a recognised medical specialty in the UK in 2006. This encompasses population-based strategies for disease prevention outlined in the global initiative founded in 2007 “Exercise is Medicine“.

What has this got to do with sports performance? There are subgroups within the population, such as athletes already taking plenty of exercise. Elite athletes differ from the general population, due to superior adaptation processes to exercise, probably with a genetic component. So are the same “normal” population-based ranges of quantified medical parameters applicable?

This is precisely the issue that arose when I was on the international medical research team investigating the development of a dope test for growth hormone (GH). Crucially, exercise is one of the major stimuli for growth hormone release from the anterior pituitary. So before we could even start investigating potential downstream markers of exogenous GH abuse, the “normal” range for elite athletes had to be established.

In a similar way, are the “normal” ranges for other hormones applicable to athletes? In a fascinating lecture delivered by Dr Kristien Boelaert, Consultant Endocrinologist, it was explained that the distribution for thyroid stimulating hormone (TSH) is affected by multiple factors, including illness, age and exercise status. So “normal” for the general population is not necessarily normal for specific subgroups.

The other issue, especially with the Endocrine system is that hormones act on a variety of tissues and so produce a variety of multi-system network effects with interactions and control feedback loops. Therefore symptoms of malfunction/maladaptation and subclinical conditions can be non specific. From a doctor’s perspective this makes Endocrinology fascinating detective work, but challenging when dealing with subgroups in the population who require a more intensive work-up and individualised approach.

larf5523

The vast majority of research studies involve exclusively male athletes, leaving female athletes under-represented (a recent study on heat adaptation in female athletes being a notable exception). Some areas of research, including my own, have been directed more towards female athletes in the case of female athlete triad, or Relative Energy Deficiency in sports (REDs). REDs is a more appropriate term as it really sums up the important points: male and female can both be affected and therefore should both be studied. There are subgroups within the general population who may not fit the “normal” range: REDs is not necessarily a clinically defined eating disorder from lecture by Professor J. Sundgot-Borgen (IOC working group on female athlete triad and IOC working group on body composition, health and performance).

No medical/physiological/metabolic parameter can be considered in isolation: in the case of REDs, it is not menstrual disturbance and bone health that are affected in isolation. For example, there is currently great debate about whether a low carbohydrate/high fat diet (ketogenic diet) can mobilise fat oxidation and potentially be a training strategy to enhance performance. Needless to say that a recent study contained no female athletes. Given that many female endurance athletes are already lean, potentially driving fat metabolism through diet manipulation may have an impact on Endocrine function, optimal health and hence sport performance. I understand that a forthcoming study will include female athletes.

So a continuum or distinct subgroups in the population? Clearly general medical principles apply to all, with a spectrum from optimal functioning, subclinical conditions through to recognised disease state. We now have evidence of distinct differences between subgroups in the population and even within these subgroups such as male and female athletes. We are moving into a world of personalised medicine, where recommendations for optimal health are tailored for individuals within specific subgroups.

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

How should we define health?

Nobody is average but what to do about it? The challenge of individualized disease prevention based on genomics

Exercise is Medicine

Enhancing Sport Performance: part 1

Keay N, Logobardi S, Ehrnborg C, Cittadini A, Rosen T, Healy ML, Dall R, Bassett E, Pentecost C, Powrie J, Boroujerdi M, Jorgensen JOL, Sacca L. Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential as a marker of GH abuse in sport: a double blind, placebo controlled study. Journal of Endocrinology and Metabolism. 85 (4) 1505-1512. 2000.

Wallace J, Cuneo R, Keay N, Sonksen P. Responses of markers of bone and collagen turover to exercise, growth hormone (GH) administration and GH withdrawal in trained adult males. Journal of Endocrinology and Metabolism 2000. 85 (1): 124-33.

Wallace J, Cuneo R, Baxter R, Orskov H, Keay N, Sonksen P. Responses of the growth hormone (GH) and insulin-like factor axis to exercise,GH administration and GH withdrawal in trained adult males: a potential test for GH abuse in sport. Journal of Endocrinology and Metabolism 1999. 84 (10): 3591-601.

Keay N, Logobardi S, Ehrnborg C, Cittadini A, Rosen T, Healy ML, Dall R, Bassett E, Pentecost C, Powrie J, Boroujerdi M, Jorgensen JOL, Sacca L. Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential usefulness as in the detection of GH abuse in sport: a double blind, placebo controlled study. Endocrine Society Conference 1999.

Wallace J, Cuneo R, Keay N. Bone markers and growth hormone abuse in athletes. Growth hormone and IGF Research, vol 8: 4: 348.

Cuneo R, Wallace J, Keay N. Use of bone markers to detect growth hormone abuse in sport. Proceedings of Annual Scientific Meeting, Endocrine Society of Australia. August 1998, vol 41, p55.

Subclinical hypothydroidism in athletes. Lecture by Dr Kristeien Boelaert at BASEM Spring Conference 2014 on the Fatigued Athlete

Optimal health: especially young athletes! Part 3 Consequences of Relative Energy Deficiency in sports Dr N.Keay, British Association Sport and exercise Medicine

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

Relative Energy Deficiency in sport (REDs) Lecture by Professor Jorum Sundgot-Borgen, BAEM Spring Conference 2015 on the Female Athlete

Effect of adaptive responses to heat exposure on exercise performance

Low Carbohydrate, High Fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers

Effects of adaptive responses to heat exposure on exercise performance

4 December 2016

To date few studies have been conducted on the effect of heat exposure to exercise performance in female athletes. With the publication of recent research, hopefully this will now change with the 2018 Commonwealth Games to be held in Queensland, Australia where athletes will have to compete in hot conditions.womenarenota

A picture of the author Tze-Huan Lei and participant while taking part in the experiment. Credit: David Wiltshire, Massey University, New Zealand

During the luteal phase (post ovulation, when progesterone levels rise) of the menstrual cycle, body temperature rises. Hence the previous suggestion “that women should avoid competition or face a disadvantage when performing exercise with heat stress during their luteal phase”. However recent research demonstrates that in eumenorrheic athletes, autonomic regulation of body temperature (skin blood flow and sweating) either at rest or during exercise is not effected by the phase of the menstrual cycle. As yet there are no studies of females athletes taking the oral contraceptive pill with respect to body temperature regulation.

A recently published study, conducted on male athletes demonstrated that episodic heat exposure over 11 days had a positive effect on regulating body temperature in hot conditions, associated with rapid onset of sweating. This heat exposure also increased skeletal muscle contractility. These findings suggest that heat adaptation could maintain and improve sport performance. The mechanism of this improvement in skeletal muscle contractility with heat exposure could be an increase in transcription of oxidative phosphorylation-associated genes resulting in increases in synthesis of ATP, muscle mass and strength. This effect was recorded amongst men exposed to 10 weeks of periodic heat stress, without any training. In other words heat alone, even without exercise improved skeletal muscle function.

The interesting findings of these studies investigating the adaptive responses produced by exposure to heat will hopefully stimulate further research to include female athletes who compete in the same challenging environmental conditions as male athletes.

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

Physiological Society report

The Journal of Physiology

Amercian Journal of Physiology

European Journal of Applied Physiology

Enhancing Sport Performance: part 1

6 November 2016

The good, the bad and the ugly

A medical perspective on clean athletes, dopers and abuse of the system

When I worked with the international medical research team investigating a method for detecting athletes doping with growth hormone (GH), I was struck by the co-operation of the medical teams and the athletes supporting this research in various countries. This project was supported by the International Olympic Committee and the drug companies manufacturing growth hormone who did not want to see this product mis-used.

growthhormone

Why would athletes seek to dope with GH? GH alters body composition by increasing lean mass and decreasing fat mass, a potential advantage for power sports. In addition to this anabolic effect, GH is potentially advantageous to physiology and metabolism in endurance sport by increasing use of lipid over glycogen as a substrate. However there are serious side effects of elevated GH levels as seen in patients suffering with acromegaly: including increased risk of diabetes mellitus, hypertension and cancer.

One of the challenges we encountered in developing a dope test for GH was that endogenously secreted growth hormone was virtually identical to the manufactured product. In addition, this peptide hormone is released episodically in a pulsatile manner and has a short plasma half life. So early on it was realised that direct measurement of growth hormone was not a reliable option, rather quantification of indirect plasma markers would be required. In turn that meant investigating the pharmacokinetic properties of these markers in exercising people.

So far so good. However what are the “normal” ranges for growth hormone and these secondary markers in elite athletes? The ranges used in the usual clinical hospital setting may not be accurate as exercise is a major stimulus for growth hormone release. Part of the reason elite athletes are better than amateur athletes is that they may have slightly different physiology and/or genetically determined physiology that responds more rapidly to training than the rest of us. So the first step was establishing what normal ranges are for growth hormone and its associated markers in elite athletes. Cue trips to Manchester velodrome with portable centrifuges, taking blood from Olympic medal winning rowers at the British Olympic Park and numerous evenings performing VO2 max tests on athletes.

Throughout this research I was struck by the desire of the elite athletes to participate in a study that would identify cheats, allowing them, as clean athletes, to compete on a level playing field. This gave those of us in medical research team extra incentive to come up with the most reliable and robust test possible. Nevertheless, we were aware that an arms race was taking place, with the dopers trying equally hard to cheat our test. Ultimately, however scientifically robust a test may be, it will not succeed if there is manipulation of the samples provided. This is what makes the alleged systemic abuse of the process so ugly.

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

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

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

Keay N, Logobardi S, Ehrnborg C, Cittadini A, Rosen T, Healy ML, Dall R, Bassett E, Pentecost C, Powrie J, Boroujerdi M, Jorgensen JOL, Sacca L. Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential as a marker of GH abuse in sport: a double blind, placebo controlled study. Journal of Endocrinology and Metabolism. 85 (4) 1505-1512. 2000.

Wallace J, Cuneo R, Keay N, Sonksen P. Responses of markers of bone and collagen turover to exercise, growth hormone (GH) administration and GH withdrawal in trained adult males. Journal of Endocrinology and Metabolism 2000. 85 (1): 124-33

Keay N. The effects of growth hormone misuse/abuse. Use and abuse of hormonal agents: Sport 1999. Vol 7, no 3, 11-12

Wallace J, Cuneo R, Baxter R, Orskov H, Keay N, Sonksen P. Responses of the growth hormone (GH) and insulin-like factor axis to exercise,GH administration and GH withdrawal in trained adult males: a potential test for GH abuse in sport. Journal of Endocrinology and Metabolism 1999. 84 (10): 3591-601

Keay N, Logobardi S, Ehrnborg C, Cittadini A, Rosen T, Healy ML, Dall R, Bassett E, Pentecost C, Powrie J, Boroujerdi M, Jorgensen JOL, Sacca L. Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential usefulness as in the detection of GH abuse in sport: a double blind, placebo controlled study. Endocrine Society Conference 1999

Wallace J, Cuneo R, Keay N. Bone markers and growth hormone abuse in athletes. Growth hormone and IGF Research, vol 8: 4: 348

Cuneo R, Wallace J, Keay N. Use of bone markers to detect growth hormone abuse in sport. Proceedings of Annual Scientific Meeting, Endocrine Society of Australia. August 1998, vol 41, p55

Enabling Sport Performance: part 2

Enhancing sports performance: part 3