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?

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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

 

 

Male Athletes: the Bare Bones of Cyclists

Chris Boardman is an Olympic gold medal winner and world record breaking cyclist. However, he explains in his biography that he retired in his early thirties with weak bones and low testosterone. At the time he was treated with medication aimed at improving his bone strength, but this severely impacted his performance on the bike.

What was the cause of this superlative male athlete’s unhealthy condition that ultimately lead to his retirement? Is this still an issue for male cyclists today? Is it limited to elite professional riders?

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Periodisation of key training factors support the Endocrine system to optimise performance

In 2014 the IOC published a description of relative energy deficiency in sports (RED-S), where nutrition intake is insufficient to cover training demands and the basic “housekeeping” activities of the body. This induces an energy-saving mode that impacts health and therefore athletic performance. The female athlete triad had been previously described as the combination of disordered eating, menstrual disruption and impaired bone health. RED-S goes beyond the female athlete triad to include a broader range of  impacts on systems other than just the bones and female hormone production. Significantly RED-S includes male athletes. Today, Chris Boardman would be diagnosed with RED-S.

Has this new information improved the identification and support of male athletes at risk of RED-S? In a recent pilot study, 5 out of 10 competitive amateur riders (Category 2 and above) were in the lowest age-matched percentile of body fat and 9 out 10 where in the lowest 6% relative to the population of similar age. Significantly, 7 out of 10 riders had below-average for age bone mineral density (BMD) in the lumbar spine, with two males having bone densities that would be low for an 85 year old.

Why is poor bone health a particular risk for competitive male cyclists? Depending on the type of exercise, beneficial adaptations include mechanical strengthening of specific parts of the skeletal system. For example, assuming good nutrition, runners tend to have strong hips, whereas rowers have more robust spines in terms of BMD and bone microarchitecture. Conversely the non-weight-bearing nature of cycling and the generally lower level of upper-body musculature reduce the mechanical loading forces though the spine: low osteogenic (bone building) stimuli. Although similar to swimming, in the sense that body weight is supported in the water, the major difference between these two forms of exercise is that in cycling, particularly for climbing, low body mass confers a performance advantage. This brings in the additional factor for bone health of potential inadequacies in nutrition and therefore consequences on hormone production.

An optimal balance of training, nutrition and recovery drives beneficial adaptations to exercise throughout the body. The body’s Endocrine system releases hormones that stimulate positive changes, such as the process of improving the efficiency of delivering and utilising oxygen and nutrients to exercising tissues, including the skeletal system. Any imbalances in periodisation between the three inputs of training, nutrition and recovery will compromise health and athletic performance.

Cyclists are at particular risk of insufficient fuelling. This may be an intentional attempt to maintain low body weight, which can lead to healthy eating becoming an unhealthy orthorexic pattern, where vital food groups for endurance sport, such as carbohydrates are excluded. There is also a practical element to fuelling adequately during long rides and refuelling afterwards. Consistency of nutrition throughout the day has been highlighted in a recent study of male endurance athletes where although an average 24 hour intake may be sufficient, if there are any significant deficits during this time, then this is reflected in increased adverse impact on catabolic Endocrine makers. In another study of male athletes if refuelling with carbohydrate and protein after training did not occur promptly, this lead to an increase in bone resorption over formation markers.

Recovery is an essential part of a training schedule, because the adaptations to exercise occur during rest. Sleep, in particular, is a major stimulus for growth hormone release, which drives positive adaptive changes in terms of body composition and bone turnover. Conversely, insufficient recovery time due to a packed schedule of training and work, places extra stresses on the Endocrine system. Getting to bed half an hour earlier than usual every day quickly adds up to an extra night’s sleep.

Does it matter if some areas of the skeleton are weaker than others? Yes, because this increases your risk of fracture, not just if you come off your bike, but also with relatively low force impacts. In the case of runners and triathletes, bone stress injuries are more likely to occur as an early warning sign of impaired bone health due to RED-S. Since low impact forces are absent in cycling, it may take a crash to reveal the strength of a rider’s bones. So potentially cyclists can develop more severe bone health issues than other athletes, before becoming aware of the situation.

If you are a male cyclist, what can you do to prevent issues of bone health and risk of developing RED-S and suboptimal performance on the bike? Watch this space! A study is planned to investigate practical and effective strategies to optimise health and performance on the bike. 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

Mechanisms for optimal health…for all athletes! BJSM 2017

Optimal health: including female athletes! Part 1 Bones BJSM 2017

Optimal health: including male athletes! Part 2 Relative Energy Deficiency in sports BJSM 2017

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

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

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

Within-day Energy Deficiency and Metabolic Perturbation in Male Endurance Athletes International Journal of Sport Nutrition and Exercise Metabolism 2018

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

Sleep for health and sports performance BJSM 2017

 

 

 

Male Cyclists: Bones, Body composition, Nutrition, Performance

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There has been much recent coverage regarding female runners suffering with health and performance issues due to relative energy deficiency in sports (RED-S). What about male athletes? A recent article about male cyclists who explained how they developed RED-S, did not receive as sympathetic a response as articles concerning female athletes. Yet multiple Endocrine network disruption in RED-S, associated with suboptimal health and performance, is equally applicable to male and female athletes.

Although competitive road cycling is excellent for cardiovascular (CV) fitness, why are male cyclists at particular risk of impaired bone health and RED-S? Cycling is a non-weight bearing type of exercise, as is swimming, so does not provide much osteogenic (bone building) stimulus. The additional element in road cycling is that, in the short term, low body weight, with associated low body fat, confers a performance advantage. However this can lead to restrictive nutrition and RED-S, that have adverse effects on health and performance, over the longer term.

A recent study looking at bone acquisition in adolescent males found that bone mass, microarchitecture and makers of bone formation were more favourable in footballers compared with cyclists and swimmers. Swimmers had the lowest Vitamin D, presumably as this is generally an indoor sport (unless you live in Australia where outdoor 50m pools abound). Another study found reduction in femoral neck bone mineral accumulation in adolescent male cyclists compared against increases over the same time frame seen in controls.

What about adult male road cyclists? When runners and cyclists were matched for age and body weight, there were no significant differences in hormone or nutrition status, yet cyclists were 7 times more likely to have osteopenia of the lumbar spine than runners. Similar results were found in another study where competitive male road cyclists were found to have reduced lumbar spine bone mineral density (BMD) for age, despite normal levels of testosterone and insulin-like growth factor 1 (IGF1), although intriguingly an inverse correlation with lumbar spine BMD and IGF1 was found. It appears that the biomechanical stress patterns on the spine in cycling are not oesteogenic in nature, which contrasts with rowing where, although also seated, the biomechanical load exerted through the spine does provide an osteogenic effect.

In addition to the non-load bearing nature of cycling on the skeleton, restrictive nutrition can contribute to suboptimal bone health. Reducing energy availability by restricting energy intake whilst increasing training load can be a strategy, especially during pre-season training to reduce body weight and body fat. Essentially, cycling up a steep incline demands less power through the pedals if your body weight is low. Nevertheless, reducing energy availability runs the risk of developing RED-S, associated Endocrine dysfunction and suboptimal bone health, on top of the non-beneficial mechanical osteogenic effect of cycling. On a practical note, with long training rides in the saddle it can be physically and practically difficult to fuel optimally. Recent research in female athletes shows that within day energy deficits magnify hormonal disruption. Could this be a factor in male cyclists where consistent fuelling is either actively avoided and/or practically difficult?

The psychological element of disordered eating has been described amongst elite male cyclists. Male cyclists, in particular, collect many metrics associated with training and racing which could be a manifestation of a drive to perfectionism. Determination and attention to detail are laudable qualities for athletes, but there is a fine line when the balance swings to behaviours and attitudes that can be detrimental to health and performance. Even starting off with good intentions can lead to problems as seen with the growing emergence of orthorexia: “clean eating”, which, ironically, becomes detrimental to health and performance with exclusion of food groups such as carbohydrates.

Exclusively practising a non weight bearing sport such as cycling although great for CV fitness, is not so good for bone health. Does this matter? Potentially injury is more likely in bike spills, which occur both in training and competition even for the most experienced bike handler. Combined with the drive for low body weight in competitive road cycling, health and performance issues can be compounded with RED-S. What are the solutions for the cyclist to support favourable body composition and bone health, which ultimately also optimises performance? A further planned study, following a current pilot study of competitive road cyclists, aims to investigate the potential beneficial effects of strength and conditioning to load the skeleton combined with a review of nutrition. See details of next study to see if you wish to participate.

For more discussion on the Endocrine aspects of Sports and Exercise Science and Medicine, BASEM Spring conference 22 March 

References

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

Optimal health: including male athletes! Part 2 Relative Energy Deficiency in sports BJSM 2017

Too healthy to ride? How clean living could slow you down Cycling Weekly 2017

Body Composition for Health and Sports Performance

Longitudinal Adaptations of Bone Mass, Geometry, and Metabolism in Adolescent Male Athletes: The PRO-BONE Study JBMR 2017

Bone Related Health Status in Adolescent Cyclists Plos 2011

Participation in road cycling vs running is associated with lower bone mineral density in men Metabolism 2008

Evaluation of the Bone Status in High-Level Cyclists Journal of Clinical Densitometry 2012

Effect of exercise training programme on bone mineral density in novice college rowers BJSM 1995

Energy Intake and Energy Expenditure of Elite Cyclists During Preseason Training Int J Sports Med 2005
Kings and Queens of the Mountains Science4Performance 2017

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

Perfectionism and Risk for Disordered Eating among Young French Male Cyclists of High Performance Perceptual and Motor Skills 2004

Kings and Queens of the Mountains Science4Performance 2017

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

Optimal Health: For All Athletes! Part 4 – Mechanisms BASEM 2017

 

 

 

 

 

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

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Unfortunately I continue to see athletes, both male and female, whose health and athletic performance is hampered due to Relative Energy Deficiency in Sports (RED-S). There have been some high profile athletes who have been very open about how RED-S has affected them, alerting younger athletes to potential pitfalls.

Does this issue warrant highlighting? Yes! The athletes I see and those that speak out are only just the tip of the iceberg. In a study of exercising females, half were found to have subtle menstrual hormone disruption such as luteal phase deficit or anovulation. A third were amenorrhoeic, with no periods at all. All women of reproductive age, whether an athlete or not, should have regular periods, otherwise there are potential serious health and performance sequaelae. However studies in both the USA and Australia have revealed that the majority of young exercising women are not aware of the link between menstrual disruption and deleterious, potentially irreversible effects on bone health.

The impact of non-integrated periodisation of training, nutrition and recovery has evolved since the early description of the female athlete triad. The constellation of amenorrhoea, disordered eating and osteoporosis is now considered to be a clinical spectrum. In turn the female athlete triad is part of a much broader picture of RED-S, which includes adverse multi-system effects beyond bone health and is also seen in male athletes.

Although an athlete may appear healthy, what are the underlying Endocrine disruptions occurring in RED-S that ultimately will impede both optimal health and performance to full potential? In general, female exercisers are more susceptible to internal and external perturbations as the female Endocrine system is more finely balanced than in males. Nevertheless, in a study of male athletes, in the short time period after completing a training session, bone turnover was adversely affected, with an increase in markers of resorption relative to formation, if an athlete did not refuel rapidly with protein and carbohydrate. In the now classic research by Loucks, 5 days of manipulated energy restricted availability, via dietary intake and exercise output, caused disruption in LH pulsatility in previously eumenorrhoeic women. From this research and subsequent studies, not only is the reproductive axis disrupted with reduced energy availability, in addition hypothalamus-pituitary-thyroid (decreased T3) and adrenal axes (increased cortisol) and decreased IGF1 due to relative GH resistance are all disrupted. These interactive hormonal dysfunctions occur even before reduction in sex steroids. A recent study demonstrated that beyond the average energy availability over a 24 hour time window, within day energy deficits in terms of duration and magnitude are associated with a greater degree of disruption of Endocrine and metabolic markers, in particular decreased oestradiol and increased cortisol. So consistency of nutrition, not only during a training season but from day to day is vital.

Although energy availability is the crucial factor in the pathophysiology of RED-S, measuring this is not practical for all athletes in terms of accuracy and cost. Clinical menstrual status in female athletes and basic Endocrine markers are proposed as being more reliable and accessible. The Endocrine system is very sensitive to internal and external perturbations, as described above, and presages performance consequences of RED-S, such as injury. An important starting point is for all female athletes is to ask themselves: are my periods regular? This is also a vital question that coaches and parents need to consider for athletes in their care. If the answer is no, then this needs to be assessed, ideally by those with experience in Sports Endocrinology.

Why are these clinical and biochemical markers of Endocrine dysfunction important for athletes? Essentially there are significant health and performance implications for athletes. As outlined in the stories of female athletes, by the time career limiting stress fractures become obvious, typically in early twenties, the Endocrine system has been in disarray for a significant time. Long term, irreversible poor bone health and adverse body composition have been established.

In my opinion, emphasis should be placed on the positive outcome of integrating periodised training, nutrition and recovery to support a functional Endocrine system and therefore optimal health and ability to reach full athletic potential. For example for female athletes, competing in sports where low body mass confers a performance advantage, such as ballet, gymnastics and road cycling, finely tuned neuromuscular skills are essential to reach maximal potential and minimise injury risk. Yet these are the athletes most at risk of developing RED-S, with consequential adverse effects on menstrual cycles, endogenous oestrogen secretion and neuromuscular function.

Rather than reading headlines about the concerning health issues amongst athletes, more guidance for athletes and those working with them, on the warning signs and how to combat RED-S are needed so that athletes can reach their full potential and the headlines become about athlete achievements.

For more discussion on the Endocrine and Metabolic aspects of Sport and Exercise Medicine, all members of multi-disciplinary team working with athletes, including athletes and coaches are welcome to the BASEM Spring Conference

BAsem2018_SpringConf_BJSM

References

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

British middle-distance runner Bobby Clay is struggling with osteoporosis but wants her experience to act as a lesson for fellow young athletes Athletics Weekly 2017

In a special AW report, former English Schools champion Jen Walsh reveals the devastation that the female athlete triad can wreak Athletics Weekly 2017

Optimal Health: Especially Young Athletes! Part 3 – Consequences of Relative Energy Deficiency in Sports BASEM 2017

Prevalence High prevalence of subtle and severe menstrual disturbances in exercising women: confirmation using daily hormone measures. Human Repro 2010

Energy deficiency, menstrual disturbances, and low bone mass: what do exercising Australian women know about the female athlete triad? Int J Sport Nutr Exerc Metab. 2012

Female adolescent athletes’ awareness of the connection between menstrual status and bone health J Pediatr Adolesc Gynecol. 2011

Optimal health: including female athletes! Part 1 Bones BJSM 2017

Optimal Health: For All Athletes! Part 4 – Mechanisms BASEM 2017

Optimal health: including male athletes! Part 2 Relative Energy Deficiency in sports BJSM 2017

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

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

Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women JCEM 2003

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

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

Body Composition for Health and Sports Performance

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

Conferences in Sport/Dance, Exercise Science and Medicine 2018

Conferences for the New Year:

BAsem2018_SpringConf_BJSM

If you are interested in any aspects of Sport/Dance, Exercise and Lifestyle Medicine here are some suggestions:

British Association of Sport and Exercise Medicine Spring Conference 22 March 2018 “Health, Hormones and Human Performance” Covering the Endocrine and Metabolic aspects of Sport, Dance, Exercise Science and Medicine. From the elite athlete to the reluctant exerciser. Aimed at all those members of the multidisciplinary team working with athletes/dancers, plus athletes/dancers and their coaches/teachers.

CPD points awarded from Faculty of Sports and Exercise Medicine FSEM

BASES British Association of Sport and Exercise Sciences CPD awarded

British Journal of Sports Medicine Quality International Education Approved

CPD points from Royal College of Physicians

CPD from REP-S

 

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Why? The balance and timing of exercise, nutrition and recovery is key to optimising health and all aspects of human performance. Intricate network interactions between the Endocrine system and metabolic signalling pathways drive these positive adaptations. However, non-integration of these lifestyle factors can disrupt signalling feedback pathways and predispose to maladaptation and potentially disease states.

What? Discussion, led by experienced clinicians and researchers will cover:

· Key role of Sports Endocrinology in health and performance

· Effects of exercise modalities on body composition and bone health

· Machine learning in interpreting biochemical & metabolomic patterns

· Endocrine & metabolic markers in assessing health & training status

· Gut metabolism in supporting health and performance

· Exercise as crucial lifestyle factor in pre-existing metabolic dysfunction

Who? This conference is relevant to all members of multidisciplinary teams supporting both reluctant exercisers and elite athletes. Medics, researchers, physiologists, physiotherapists, nutritionists, psychologists, coaches, athletes. All welcome.

Health, Hormones and Human Performance will be a conference of interest to all those involved with aspiring and elite athletes, including dancers (National Institute of Dance Medicine and Science NIDMS) and those supporting reluctant exercisers through Lifestyle Medicine.

Latest news from BASEM. Interview with BASEM Today Issue 41 – Winter 2017

 

Wales Exercise Medicine Symposium by Cardiff Sports & Exercise Medicine Society 27/1/18. This includes Dr Peter Brukner, founder of the Olympic Sports Medicine Park in Melbourne, and an afternoon session discussing the female athlete through the lifespan. CPD points applied for from the Royal College of Physicians, the Faculty of Sports and Exercise Medicine, REPs and the Royal College Of General Practitioners.

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Women in Sport and Exercise Conference 2018  13-14 June Organised by The Women in Sport and Exercise Academic Network and attracting British Association of Sport and Exercise Sciences (BASES) CPD points.

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Body Composition for Health and Sports Performance

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Body Composition from DEXA scan

Focusing on changes in body weight and body mass index (BMI) alone, as outcome measures of lifestyle interventions, ignores the beneficial multi-system and psychological effects of lifestyle medicine, in particular exercise. This includes advantageous changes in body composition for health and performance.

Why is body composition important? Because not all weight is equal in terms of tissue composition and distribution. To support optimal health, favourable levels of lean mass  versus fat mass decreases the risk of sarcopenia, associated bone loss and metabolic syndrome. For athletes, high lean mass coupled with low fat mass is related to improved athletic performance, especially in disciplines where strength to weight ratio a major consideration and/or those disciplines such as gymnastics and ballet where an aesthetic component confers a performance advantage.

The range of methods for measuring body composition have advantages and disadvantages in terms of accuracy, accessibility and expense. Although accurate in experienced hands, skin fold measurements are limited to giving a measure of subcutaneous fat. Impedance scales have the advantage of giving a measure of both total and visceral fat percentage, however accuracy is dependent on hydration status, amongst other variable factors. Dual-Energy X-Ray Absorptiometry (DEXA) scan is the “gold standard” for measuring body composition to include bone, lean and fat: both total and visceral. DEXA scan is relatively inexpensive and very low radiation dose compared to traditional X ray or computerised tomography (CT). This method of assessing body composition during training seasons is used by some professional sports teams. The illustration above shows a trained male with total fat in the athletic range. Although simple to measure, BMI does not accurately reflect body composition. All methods of assessing body composition can potentially have role in monitoring changes, for example over training seasons, and trends for individuals rather than relying on the absolute values of metrics measured.

How to go about optimising body composition? Combined exercise and nutritional strategies trigger and reinforce favourable metabolic and Endocrine signalling pathways. The detail of these lifestyle strategies will depend on the clinical context and the objectives of the individual: ranging from a sedentary person trying to improve health and well being, to an athlete aiming to improve sport performance. In all scenarios protein intake is an important factor in supporting lean mass, alongside tailored exercise/training. Temporal considerations for optimising body composition in athletes include the age of the athlete and targeting key competitions during a training cycle and in long term over athletic career. Ultimately optimising body composition has to translate to improved athletic performance for the endurance athlete. So aiming for “high quality weight loss” with retention or even improved lean mass, is more likely to support performance, rather than focusing on fat mass loss in isolation, which may occur in any case as a secondary consequence of integrated periodised training, nutrition and recovery. Striving for weight loss and reduced fat mass without careful monitoring and attention to effects on performance, can run the risk of athletes developing relative energy deficiency in sports (RED-S). Female athletes with functional hypothalamic amenorrhoea have been shown to decreased levels not only of lean and fat mass, but in addition reduced metabolically active brown fat and the associated hormone isirin which promotes fat “browning” and impacts bone mineralisation. In addition, there are differences between male and female athletes to be considered in terms of body composition and cycling performance.

From middle-age, both lean mass and bone mineral density (BMD) decline: sarcopenia and bone health intertwined. In order to mitigate against these changes, resistance exercise is particularly beneficial to stimulate muscle and load the skeleton and for metabolic and cognitive benefits. BMI is particularly misleading as a metric to assess risk of disease in menopausal women. Rather, the finer detail of body composition, for example visceral fat area, is more informative in terms of metabolic and psychological health.

Body composition is a more reliable indicator of health than body weight or BMI. Nevertheless body composition in isolation is not the sole determinant of health and performance. Rather body composition is just one of many multi-system effects mediated by integrated metabolic and Endocrine signalling pathways. These network effects are driven by lifestyle factors including exercise, nutrition and recovery, to determine health and sports performance.

For more discussion and debate on the role of body composition for health and performance BASEM Spring Conference 2018 6 CPD points from FSEM and BJSM approved for international education

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References

Challenging those hard to shift, big fat obesity risks BMJ 2017; 359: j5303 British Journal of Medicine 2017

Lifestyle Choices for optimising health: exercise, nutrition, sleep British Journal of Sport Medicine 2107

One road to Rome: Exercise British Journal of Sport Medicine 2107

Current Status of Body Composition Assessment in Sport Review and Position Statement on Behalf of the Ad Hoc Research Working Group on Body Composition Health and Performance, Under the Auspices of the I.O.C.Medical Commission

International society of sports nutrition position stand: diets and body composition Journal of the International Society of Sports Nutrition 2017
Case-Study: Body Composition Periodization in an Olympic-Level Female Middle-Distance Runner Over a 9-Year Career International Journal of Sport Nutrition and Exercise Metabolism 2017

Body composition assessment of English Premier League soccer players: a comparative DXA analysis of first team, U21 and U18 squads Journal of Sports Sciences

Protein Recommendations for Weight Loss in Elite Athletes: A Focus on Body Composition and Performance International Journal of Sport Nutrition and Exercise Metabolism 2017

Optimal Health: For All Athletes! Part 4 – Mechanisms British Association for Sport and Exercise Medicine 2017

Effect of Chronic Athletic Activity on Brown Fat in Young Women Plos One 2106

Irisin levels are lower in young amenorrheic athletes compared with eumenorrheic athletes and non-athletes and are associated with bone density and strength estimates Plos One

Kings and Queens of the Mountains Science4Performance

Low bone mineral density in middle-aged women: a red flag for sarcopenia Menopause 2017

Resistance training – an underutilised drug available in everybody’s medicine cabinet BJSM 2017

Benefits of resistance training in physically frail elderly: a systematic review Ageing Clinical and Experimental Research 2017

Is BMI a valid measure of obesity in postmenopausal women? Menopause 2017

Association of visceral fat area with the presence of depressive symptoms in Chinese postmenopausal women with normal glucose tolerance Menopause 2017

 

 

 

Health and Performance during Lifespan: latest research

LifeSeasonDay

Your lifespan depends on genetic and key lifestyle choices

Lifespan is dependent on a range of genetic factors combined with lifestyle choices. For example a recent study reported that an increase in one body mass index unit reduced lifespan by 7 months, whilst 1 year of education increased lifespan by 11 months. Physical activity was shown to be a particularly important lifestyle factor through its action on preventing age-related telomere shortening and thus reducing of cellular ageing by 9 years. Nevertheless, even though males and females have essentially identical genomes, genetic expression differs. This results in different disease susceptibilities and evolutionary selection pressures. More studies involving female participants are required!

Circadian clock

Much evidence is emerging about the importance of paying respect to our internal biological clocks when considering the timing of lifestyle factors such as eating, activity and sleep. For example intermittent fasting, especially during the night, and time restricted eating during the day enables metabolic flexibility. In other words, eating within a daylight time window will support favourable metabolism and body composition. No midnight snacks!

For athletes, even more care needs be given to timing of nutrition to support athletic performance. In the short term there is evidence that rapid refuelling after training with a combination of carbohydrate and protein favours a positive balance of bone turnover that supports bone health and prevents injury in the longer term. Periodised nutrition over a training season, integrated with exercise and recovery, is important in order to benefit from training adaptations and optimise athletic performance.

Protein intake in athletes and non athletes

Recovering from injury can be a frustrating time and some athletes may be tempted to reduce food intake to compensate for reduced training. However, recommendations are to maintain and even increase protein consumption to prevent a loss of lean mass and disruption of metabolic signalling. In the case of combined lifestyle interventions, such as nutrition and exercise aimed at reducing body weight, these should be directed at improving body composition. Adequate protein intake alongside exercise will maintain lean mass in order to minimise the risk of sarcopenia and associated bone loss which can occur during hypocaloric regimes. Good protein intake is important for bone health to support bone mineral density and reduce the risk of osteoporosis and fracture.

Adolescent Athlete

In the young athlete, integrated periodisation of training, nutrition and recovery is of particular importance, not only to support health and performance, but as an injury prevention strategy.  Sufficient sleep and nutrition to match training demands are key.

Differences between circadian phenotype and performance in athletes

For everyone, whether athlete or reluctant exerciser, balancing and timing key lifestyle choices of exercise, nutrition and sleep are key for optimising health and performance. However there are individual differences when it comes to the best time for athletes to perform, according to circadian phenotype/chronotype. In other words personal biological clocks which run on biological time. An individual’s performance can vary by as much as 26% depending on the time of day relative to one’s entrained waking time.

Later in Life

Ageing can be can be confused with loss of fitness and ability to perform activities of daily living. Although a degree of loss of fitness does occur with increasing age, this can be prevented to a certain degree and certainly delayed with physical activity. Exercise attenuates sarcopenia, which supports bone mineral density with the added benefit of improved proprioception, helping to reduce risk of falls and potential fracture; not to mention the psychological benefits of exercise.

 

For more discussion on Health Hormones and Human Performance come to British Association of Sport and Exercise Medicine Spring Conference 

BAsem2018_SpringConf_BJSM

References

Genome-wide meta-analysis associates HLA-DQA1/DRB1 and LPA and lifestyle factors with human longevity Nature Communications 2017

Physical activity and telomere length in U.S. men and women: An NHANES investigation Preventive Medicine 2017

The landscape of sex-differential transcriptome and its consequent selection in human adults BMC Biology 2017

Temporal considerations in Endocrine/Metabolic interactions Part 1 British Journal of Sport and Exercise Medicine, October 2017

Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting Obesity 2017

Temporal considerations in Endocrine/Metabolic interactions Part 2 British Journal of Sport and Exercise Medicine, October 2017

Time-restricted eating may yield moderate weight loss in obesity Endocrine Today 2017

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

Periodized Nutrition for Athletes Sports Medicine 2017

Internal Biological Clocks and Sport Performance British Journal of Sport and Exercise Medicine, October 2017

Nutritional support for injuries requiring reduced activity Sports in Science Exchange 2017

Balance fat and muscle to keep bones healthy, study suggests NTU October 2017

Dietary Protein Intake above the Current RDA and Bone Health: A Systematic Review and Meta-Analysis Journal of the American College of Nutrition 2017

Too little sleep and an unhealthy diet could increase the risk of sustaining a new injury in adolescent elite athletes Scandinavian Journal of Medicine & Science in Sports

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

The impact of circadian phenotype and time since awakening on diurnal performance in athletes Current Biology

Successful Ageing British Association of Sport and Exercise Medicine 2017

Focus on physical activity can help avoid unnecessary social care BMJ October 2017

Biochemical Pathways of Sarcopenia and Their Modulation by Physical Exercise: A Narrative Review Frontiers in Medicine 2017

 

Lifestyle Choices

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Lifestyle Choices: Exercise, Nutrition, Sleep

Lifestyle factors of exercise, nutrition and sleep are vital for optimising health. In the illustration shown, ideally we should be in the green zone representing a balance between these lifestyle factors. Slipping into the peripheral red zone represents an imbalance: either too much or too little of any of these three elements. In particular exercise is of paramount importance being the most effective way of producing beneficial, multi-system effects mediated via the Endocrine system to optimise health and playing an important role in chronic disease prevention. However, it is not just a matter of what, but when: timing is crucial in integrating lifestyle factors with internal biological clocks. Beyond these guiding principles, personal preference and choice is emerging as being just as important as the lifestyle factor itself.

In a fascinating study, 58 participants were given either a prescribed exercise session, or a choice of exercise. Afterwards the participants were presented with a choice of foods, which they believed was simply as way of thank you for taking part in the exercise study. Post exercise, in those given no choice exercise, higher energy intake of food was consumed with larger proportion of “unhealthy” food compared to choice exercise group. The choice exercise group reported greater value and enjoyment of the exercise session. Thus autonomous choice of exercise not only provides positive reinforcement of exercising, but subsequent food choice is improved.

This concept of facilitating self determination, particularly when it comes to exercise was explored at the the recent annual British Association of Sport and Exercise conference. “Practicalities of intervention design, adherence and motivation” was presented by Dr Carly McKay from Bath University, who described how empowering people to make choices is far more likely to mean they will adhere to those lifestyle options that will optimise health.

What about the optimal timing of exercise which might improve motivation and performance? Well this depends on the context and what you are trying to achieve. In the case of training for competition and competition itself, optimal performance tends to be early evening, providing the most favourable hormonal milieu. Although in theory the morning diurnal release of cortisol might help with exercise, the downside is that this may interfere with blood glucose regulation. Furthermore, focusing on just one hormone in the Endocrine system, rather than the integrated function of the hypothalamic-pituitary axis could be misleading. Although due respect should be paid to internal biological clocks, to prevent circadian misalignment between internal pacemakers and external factors; equally becoming too obsessive about sticking to a rigid schedule would psychologically take away that essential element of choice. Practicality is a very important consideration and a degree of flexibility when planning the timing of exercise. For example, my choice of cardiovascualar exercise is swimming, which I fit in according to work commitments and when public lane swimming is available. Fortunately whilst at the BASEM conference in Bath, these practical conditions were met during the lunch break to take advantage of the 50m pool at Bath University. Pragmatic, not dogmatic when it comes to timing of exercise.

Timing of nutrition post exhaustive exercise is an important factor in supporting bone health. Immediate, rather than delayed refuelling with carbohydrate and protein is more advantageous in the balance of bone turnover markers; favouring formation over resorption. In the longer term, prolonged low energy availability as in the situation of relative energy deficiency in sport (RED-S) has a potentially irreversible adverse effect on bone health. In terms of the timing of meals, not eating too close to going to sleep, ideally 2 hours before melatonin release, is best for metabolic health.

Backing up the lifestyle choices of exercise and nutrition is sleep. Timing, duration and quality of sleep is essential for many aspects of health such as hormonal release of growth hormone, functional immunity and cognitive function. Certainly it is well recognised that shift workers, with circadian misalignment: disturbed sleep patterns relative to intrinsic biological clocks, are more at risk of developing cardio-metabolic disease.

In summary, a prescriptive approach to lifestyle factors could be counter productive. Discussing options and encouraging individuals to make their own informed and personal choices is far more likely to enable that person to take responsibility for their health and adhere to changes in lifestyle that are beneficial for their health. Having worked in hospital based NHS diabetic clinics for many years, I appreciate that supporting reluctant exercisers is not always an easy task. Equally it can be difficult to distinguish between the effects of ageing and loss of fitness. However, this does not mean that this supportive and inclusive approach should be abandoned. Rather, encouraging people to participate in decision making that they feel leads to options that are realistic and beneficial, is the approach most likely to work, especially in the long term.

“If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health.”
— Hippocrates

 

For more discussion on Health Hormones and Human Performance come to British Association of Sport and Exercise Medicine Spring Conference 

BAsem2018_SpringConf_BJSM

References

Presentations

One road to Rome: Exercise Dr N. Keay, British Journal of Sports Medicine 2017

Endocrine system: balance and interplay in response to exercise training Dr N. Keay 2017

Temporal considerations in Endocrine/Metabolic interactions Part 1 Dr N. Keay, British Journal of Sports Medicine 2017

Temporal considerations in Endocrine/Metabolic interactions Part 2 Dr N. Keay, British Journal of Sports Medicine 2017

Internal Biological Clocks and Sport Performance Dr N. Keay, British Association of Sport and Exercise Medicine 2017

Providing Choice in Exercise Influences Food Intake at the Subsequent Meal Medicine & Science in Sports & Exercise October 2017

BASEM/FSEM Annual Conference 2017, Assembly Rooms, Bath

Addiction to Exercise – what distinguishes a healthy level of commitment from exercise addiction? Dr N. Keay, British Journal of Sports Medicine 2017

The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism Translational Journal of the American College of Sports Medicine October 2107

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

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

Focus on physical activity can help avoid unnecessary social care British Medical Journal October 2017

Internal Biological Clocks and Sport Performance

A Nobel Prize was awarded this week to researchers who uncovered the molecular mechanisms controlling circadian rhythm: our internal biological clock.

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Circadian Hormone Release

These mechanisms rely on negative feedback loops found in many biological systems where periodicity of gene expression is key, such as the Endocrine system. Internal biological clocks allow for anticipation of the requirements from body systems at different times of the day and the ability to adapt to changes in external lifestyle factors. What is the clinical significance of biochronometers?

The importance of integration of lifestyle factors, such as timing of eating, activity and sleep with our internal biological clocks is revealed in situations of circadian misalignment that lead to suboptimal health and disease states in the longer term.

Consideration of our biochronometers is especially important for athletes in order to synchronise periodised training, nutrition and recovery and thus optimise health and sports performance.

Athletic Performance Performance in a cycle time trial was found to be better in the evening, rather than the morning, proposed to be due to a more favourable endogenous hormonal and metabolic internal milieu. Certainly there were some disgruntled swimmers at an international event, when the usual pattern of morning heats and evenings finals was switched, to accommodate television viewing spectators.

Female athletes: menstrual cycle/training season Women have an extra layer of endogenous biological periodicity in the form of the menstrual cycle controlled by temporal changes of hormone release in the hypothamalmus-pituitary-ovarian Endocrine axis. Changes in external factors of training load, nutrition and recovery are detected by the neuroendocrine gatekeeper, the hypothalamus, which produces an appropriate change in frequency and amplitude of GnRH (gonadotrophin releasing hormone), which in turn impacts the pulsatility of LH (lutenising hormone) release from the pituitary and hence the phases of the menstrual cycle, in particular ovulation. Even short term reduction of energy availability in eumenorrhoeic female athletes can inhibit LH pulsatility frequency and release of other hormones such as IGF1. Disrupted release of sex steroids and IGF1 has a negative effect on bone turnover: increased resorption and decreased formation. Active females have been found more susceptible to reduction in energy availability impacting bone metabolism than their male counterparts.

Another consequence of the phasic nature of the menstrual cycle relating to external factors such as exercise, is that injury risk could be linked to changes in the expression of receptors for for sex steroids oestrogen and progesterone in skeletal muscle. Certainly during pregnancy and the post partum period, relaxin hormone increases the laxity of soft tissues, such as ligaments, and hence maintenance stretching, rather than seeking to increase flexibility, is recommended to prevent injury, .

In order to produce desired temporal adaptive changes in response to exercise training, signalling pathways mediated by reactive oxidative species and inflammatory markers are stimulated in the short term, with supportive Endocrine interactions in the longer term. However, an over-response can impair adaptive changes and impact other biological systems such as the immune system. This maladaptive response could occur as a result of non-integrated periodisation of training, nutrition and recovery in athletes and, in the case of female athletes, oral contraceptive pill use has been implicated, as this effectively imposes a medical menopause, preventing the phasic release of endogenous hormones.

Considering a longer time scale, such as a training season, female athletes were found to have a more significant fall ferritin during than male athletes. Low normal iron does not necessarily correlate to iron deficiency anaemia, but low levels in athletes can impact bone health. Supplementation with vitamin C to improve absorption may help, although iron overload can have deleterious effects. As training intensity increases as the season progresses, six monthly haematological reviews for female athletes were recommended in this study.

Changes in set point feedback Feedback control of the Endocrine system, for example the hypothalamic-pituitary-thyroid axis is dynamic: both anticipatory and adaptive, depending on internal and external inputs. However, presentation of a prolonged stimulus can result in maladaptation in the longer term. For example, disruption of signalling pathways leading to hyperinsulinaemia results in insulin resistance, which represents the underlying pathophysiological mechanism of obesity and the metabolic syndrome. In other words a situation of tachyphylaxis, where prolonged, repeated stimulus over time results in insensitivity to the original stimulus. This also applies to the nature of exercise training over a training season and diets that exclude a major food type: temporal variety is key.

Lifespan (prematurity, ageing) Changes during the lifespan represent an important biochronometer. Premature and small-for-dates babies are at risk of long term metabolic and Endocrine dysfunction, potentially due to intrauterine reprogramming of the hypothalamic-pituitary axis. At the other end of the biological time scale, with advancing age, DNA methylation and changes in epigenetic expression occur. It has been suggested that this age related methylation drift could be delayed with calorie restriction. Melatonin, a key player in intrinsic biological time keeping has been proposed to attenuate bone resorption by reducing relative oxidative stress. This would potentially explain why shift workers with disrupted sleep patterns are reported to be at risk not only of metabolic dysfunction, but also impaired bone health. Disrupted sleep patterns are a concern for athletes, especially those whose training and competition schedule involve frequent international travel across time zones.

In summary, respecting your internal biological clocks and integrating your lifestyle and your training, nutrition and recovery with these intrinsic pacemakers in mind will optimise health and performance.

References

The Nobel Prize in Physiology or Medicine 2017

Circadian clock control of endocrine factors Nat. Rev. Endocrinol

Temporal considerations in Endocrine/Metabolic interactions Part 1 Dr N. Keay, British Journal of Sports Medicine 2017

Temporal considerations in Endocrine/Metabolic interactions Part 2 Dr N. Keay, British Journal of Sports Medicine 2017

Athletic Fatigue: Part 2 Dr N. Keay 2017

Effect of Time of Day on Performance, Hormonal and Metabolic Response during a 1000-M Cycling Time Trial Plos One 2017

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

Effects of reduced energy availability on bone metabolism in women and men Bone 2017

Expression of sex steroid hormone receptors in human skeletal muscle during the menstrual cycle Acta Physiol (Oxf). 2017

Endocrine system: balance and interplay in response to exercise training

Kynurenic acid is reduced in females and oral contraceptive users: Implications for depression Science Direct 2017

Oxidative Stress in Female Athletes Using Combined Oral Contraceptives Sports Medicine

Iron monitoring of male and female rugby sevens players over an international season J Sports Med Phys Fitness. 2017

Thyroid Allostasis–Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming Frontiers in Endocrinology 2017

Stress- and allostasis-induced brain plasticity Annu Rev Med

Optimising Health and Athletic Performance Dr N. Keay 2017

Long-term metabolic risk among children born premature or small for gestational age Nature Reviews Endocrinology 2017

Caloric restriction delays age-related methylation drift Nature Communications 2017

Melatonin at pharmacological concentrations suppresses osteoclastogenesis via the attenuation of intracellular ROS Osteoporosis International 2017

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

 

Optimising Health and Athletic Performance

FactorsWordCloud4

In order to improve sports performance, athletes periodise their training, nutrition and recovery within the context of a training season. For those not in exercise training, these controllable lifestyle factors correspond to exercise, diet and sleep, which require modification during the lifespan. In old money, this was called preventative medicine. Taking this a step further, rather than preventing disease, this proactive, personalised approach optimises health. Health should be a positive combination of physical, mental and social well being, not simply an absence of illness.

Failure to balance these lifestyle factors in an integrated fashion leads to negative outcomes. An athlete may experience maladaptation, rather than the desired adaptations to exercise training. For non-athletes an adverse combination of lifestyle factors can lead to suboptimal health and a predisposition to developing chronic disease.

What are the fundamental pathophysiological mechanisms involved in the aetiology of the clinical spectrum of suboptimal health, suboptimal sports performance and chronic disease?

Inflammation A degree of systemic inflammation and oxidative stress induced by exercise training is required to drive desired adaptations to support improved sport performance. However, prolonged, elevated levels of inflammation have adverse effects on health and underpin many chronic disease states. For example, inflammation is a contributing pathophysiological factor in the development of atherosclerosis and atherothrombosis in cardiovascular disease. What drives this over-response of the inflammatory process? Any combination of adverse lifestyle factors. Adipose tissue has an Endocrine function, releasing a subgroup of cytokines: adipokines which have peripheral and central signalling roles in energy homeostasis and inflammation. In a study of Belgian children, pro-inflammatory energy related biomarkers (high leptin and low adiponectin) were associated with decreased heart rate variability and hence in the long term increased risk of cardiovascular disease. For those with a pre-existing chronic inflammatory condition, response to treatment can be optimised with personalised lifestyle interventions.

Metabolism Non-integrated lifestyle factors can disrupt signalling pathways involved in glucose regulation, which can result in hyperinsulinaeamia and insulin resistance. This is the underlying pathological process in the aetiology of metabolic syndrome and metabolic inflexibility. Non-pharmacological interventions such as exercise and nutrition, synchronised with endogenous circadian rhythms, can improve these signalling pathways associated with insulin sensitivity at the mitochondrial level.

Intriguingly, evidence is emerging of the interaction between osteocalcin and insulin, in other words an Endocrine feedback mechanism linking bone and metabolic health. This is reflected clinically with increased fracture risk found amongst type 2 diabetics (T2DM) with longer duration and higher HbA1C.

Hormone imbalance The hypothalamus is the neuroendocrine gatekeeper of the Endocrine system. Internal feedback and external stimuli are integrated by the hypothalamus to produce an appropriate Endocrine response from the pituitary gland. The pathogenesis of metabolic syndrome involves disruption to the neuroendocrine control of energy homeostasis with resistance to hormones secreted from adipose tissue (leptin) and the stomach (ghrelin). Further evidence for the important network effects between the Endocrine and metabolic systems comes from polycystic ovarian syndrome (PCOS). Although women with this condition typically present to the Endocrine clinic, the underlying aetiology is metabolic dysfunction with insulin resistance disrupting the hypothamic-pituitary-ovarian axis. The same pathophysiology of disrupted metabolic signalling adversely impacting the hypothalamic-pituitary-gonadal axis also applies to males.

In athletes, the exact same signalling pathways and neuroendocrine systems are involved in the development of relative energy deficiency in sports (RED-S) where the underlying aetiology is imbalance in the periodisation of training load, nutrition and recovery.

Gastrointestinal tract In addition to malabsorption issues such as coeliac disease and non-gluten wheat sensitivity, there is emerging evidence that the composition and diversity of the gut microbiota plays a significant role in health. The microbiome of professional athletes differs from sedentary people, especially at a functional metabolic level. Conversely, an adverse gut microbiome is implicated in the pathogenesis of metabolic dysfunction such as obesity and T2DM, via modulation of enteroendocrine hormones regulating appetite centrally and insulin secretion peripherally.

Circadian disregulation As previously discussed, it is not just a question of what but WHEN you eat, sleep and exercise. If there is conflict in the timing of these lifestyle activities with internal biological clocks, then this can disrupt metabolic and endocrine signally. For example, in children curtailed sleep can impact glucose control and insulin sensitivity, predisposing to risk of developing T2DM. Eating too close to the onset of melatonin release in the evening can cause adverse body composition, irrespective of what you eat and activity levels. In those with pre-existing metabolic dysfunction, such as PCOS, timing of meals has an effect on insulin levels and hence reproductive Endocrine function. The immune system displays circadian rhythmicity which integrated with external cues (for example when we eat/exercise/sleep) optimises our immune response. For athletes competing in high intensity races, this may be more favourable in terms of Endocrine and metabolic status in the evening.

Psychology Psychological stress impacts the key pathophysiological mechanisms outlined above: metabolic signalling, inflammation and neuroendocrine regulation, which contribute to Endocrine and metabolic dysfunction. Fortunately stress is a modifiable lifestyle risk factor. In the case of functional hypothalamic amenorrhoea (where nutrition/exercise/sleep are balanced), psychological intervention can reverse this situation.

Conclusion Putting this all together, if the modifiable lifestyle factors of exercise, nutrition, sleep are optimised in terms of composition and timing, this improves metabolic and Endocrine signalling pathways, including neuroendocrine regulation. Preventative Medicine going beyond preventing disease; it optimises health.

BASEM annual conference 22/3/18: Health, Hormones and Human Performance

Presentations

References

Athletic Fatigue: Part 2 Dr N. Keay

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

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

Saturated fat does not clog the arteries: coronary heart disease is a chronic inflammatory condition, the risk of which can be effectively reduced from healthy lifestyle interventions British Journal of Sports Medicine 2017

Longitudinal Associations of Leptin and Adiponectin with Heart Rate Variability in Children Frontiers in Physiology 2017

A Proposal for a Study on Treatment Selection and Lifestyle Recommendations in Chronic Inflammatory Diseases: A Danish Multidisciplinary Collaboration on Prognostic Factors and Personalised Medicine Nutrients 2017

Assessment of Metabolic Flexibility by Means of Measuring Blood Lactate, Fat, and Carbohydrate Oxidation Responses to Exercise in Professional Endurance Athletes and Less-Fit Individuals Sports Medicine 2017

Skeletal muscle mitochondria as a target to prevent or treat type 2 diabetes mellitus Nature Reviews Endocrinology

Insulin and osteocalcin: further evidence for a mutual cross-talk Endocrine 2017

HbA1c levels, diabetes duration linked to fracture risk Endocrine Today 2017

The cellular and molecular bases of leptin and ghrelin resistance in obesity Nature Reviews Endocrinology 2017

Metabolic and Endocrine System Networks Dr N. Keay

Adiponectin and resistin: potential metabolic signals affecting hypothalamo-pituitary gonadal axis in females and males of different species Reproduction 2017

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

Ubiquitous Microbiome: impact on health, sport performance and disease Dr N. Keay

The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level Gut. BMJ

Interplay between gut microbiota, its metabolites and human metabolism: Dissecting cause from consequence Trends in Food Science & Technology 2016

Temporal considerations in Endocrine/Metabolic interactions Part 1 Dr N. Keay, British Journal of Sports Medicine 2017

Temporal considerations in Endocrine/Metabolic interactions Part 2 Dr N. Keay, British Journal of Sports Medicine 2017

Sleep Duration and Risk of Type 2 Diabetes Paediatrics 2017

Later circadian timing of food intake is associated with increased body fat Am J Clin Nutr. 2017

Effects of caloric intake timing on insulin resistance and hyperandrogenism in lean women with polycystic ovary syndrome Clin Sci (London)

Immunity around the clock Science

Effect of Time of Day on Performance, Hormonal and Metabolic Response during a 1000-M Cycling Time Trial PLOS

Type 2 diabetes mellitus and psychological stress — a modifiable risk factor Nature Reviews Endocrinology 2017

Recovery of ovarian activity in women with functional hypothalamic amenorrhea who were treated with cognitive behaviour therapy Fertil Steril