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.

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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.

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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.

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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

 

 

Temporal considerations in Endocrine/Metabolic interactions Part 1

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

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

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

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

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

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

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

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

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

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

References

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

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

Metabolic and Endocrine System Networks Dr N. Keay

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

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

Factors Impacting Bone Development Dr N. Keay

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

Sleep Duration and Telomere Length in Children Journal of Paediatrics 2017

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

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

Successful Ageing Dr N. Keay, British Association of Sport and Exercise Medicine 2017

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

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

 

 

 

 

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

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“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.

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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

Optimising Health, Fitness and Sports Performance for young people

Version 2Young people need information in order to make life decisions on their health, fitness and sport training with the support of their families, teachers and coaches.

As discussed in my previous blog anima sana in corpore sano, exercise has a positive effect on all aspects of health: physical, mental and social. The beneficial impact of exercise is particularly important during adolescence where bodies and minds are changing. This time period presents a window of opportunity for young people to optimise health and fitness, both in the short term and long term.

The physical benefits of exercise for young people include development of peak bone mass, body composition and enhanced cardio-metabolic health. Exercise in young people has also been shown to support cognitive ability and psychological wellbeing.

Optimising health and all aspects of fitness in young athletes is especially important in order to train and compete successfully. During this phase of growth and development, any imbalances in training, combined with changes in proportions and unfused growth plates can render young athletes more susceptible to overuse injuries. A training strategy for injury prevention in this age group includes development of neuromuscular skills when neuroplasticity is available. Pilates is an excellent form of exercise to support sport performance.

In athletes where low body weight is an advantage for aesthetic reasons or where this confers a competitive advantage, this can lead to relative energy deficiency in sport (RED-S). Previously known as the female athlete triad, this was renamed as male athletes can also be effected. The consequences of this relative energy deficiency state are negative effects on metabolic rate, menstrual function, bone health, protein synthesis and immunity. If this situation arises in young athletes, then this is of concern for current health and may have consequences for health moving into adulthood.

A well informed young person can make decisions to optimise health, fitness and sports performance.

Link to Workshops

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

Optimal Health: Especially Young Athletes! Part 3 – Consequences of Relative Energy Deficiency in Sports Dr N. Keay, British Association Sport and Exercise Medicine 13/4/17

Report from Chief Medical Officer

Cognitive benefits of exercise

Injuries in young athletes

Young people: neuromuscular skills for sports performance

IOC consensus statement\

Exercise and fitness in young people – what factors contribute to long term health? Dr N. Keay, British Journal of Sports Medicine