“Sleep is the chief nourisher in life’s great feast”

Macbeth, Shakespeare

At the start of every year there is always a lot of talk about refraining from certain activities like drinking alcohol, advice about eating a particular way, or recommendations to do certain types/amount of exercise. Trends in these lifestyle choices may come and go, but there is one behaviour that remains constant to achieve optimal health. Sleep.

In my book “Hormones, Health and Human Potential: A guide to understanding your hormones to optimise your health and performance” I discuss how our lifestyle choices and behaviours around sleep, exercise and nutrition influence hormone networks and consequently our health.

Illustration from “Hormones, Health and Human Potential”

Sleep for hormone health

Why is sleep such an essential component for health? Although being asleep is a physical state of inactivity, it is when many hormone networks are at their most active. For example, one of the main stimuli for growth hormone (GH) release is sleep. Despite its name, GH is not just about growth in children. All adults continue to produce GH and this is an important anabolic (tissue building) hormone. GH maintains a healthy body composition: favouring muscle over fat deposition. GH also plays a role in bone health.

Sleep for fitness

Another stimulus for GH release is exercise. However, you don’t get fitter in real time while you exercise. You get fitter when you are asleep. After stopping exercise and during sleep these two combined stimuli for GH release drive the positive adaptations to exercise. Sleep enables you to become citius, altius, fortius. 

Sleep for sex steroid hormone networks

Sleep is also essential for other hormone networks, such as those of the reproductive axis, in both men and women. Studies show that men who have reduced sleep tend to have lower levels of testosterone and poorer bone health. Essentially if you do not have sufficient quality and quantity of sleep this has a negative effect on many aspects of both physical and mental health.

Sleep for metabolic health

Hormones that control appetite and satiety are linked with the sleep/wake cycle. People who have disrupted sleep patterns are more likely to struggle with blood glucose and weight control.

Timing of sleep

The timing of sleep is also important. Hormone networks run on a variety of internal biological clocks, known as biochronometers. The trick is to try and synchronise the timing of your behaviours with these internal biochronometers. If you have an “scheduling conflict” between external and internal clocks, this leads to a situation of circadian misalignment. Circadian misalignment can lead to many adverse consequences on mental and physical health, including metabolic and cardiovascular health. This negative combination can lead to metabolic syndrome which increases the risk of type 2 diabetes mellitus, cardiovascular disease and high blood pressure.

Consequences of disrupted sleep patterns

Shift workers, for example junior doctors, are at risk of developing circadian misalignment. Disrupted sleep patterns, clashing with internal hormone timing becomes a vicious circle. Poor sleep interferes with the diurnal variation of cortisol, which peaks as an awakening response. Disruption of this cortisol awakening response can disrupt subsequent night sleeping.

A degree of circadian entrainment is possible. In other words, our hormone clocks can adapt to slight changes in sleeping patterns. For example, getting up early for exercise training. It is also possible to reset internal biological clocks, as we do after a long-haul flight. This is because in our brain we have a biological light sensor which has direct communication with the manager of the hormone orchestra, conveniently situated in very close proximity in the brain. The timing of daily hormone release can be reset to correspond with local night and day timing. This contrasts to the situation of doing shift work, where you are continuously in conflict with night/day timing and internal hormone clocks.

Top tips for sleep to optimise hormone health

So, if there is one behaviour that you are going to improve this year, it should be sleep.  

Sleep hygiene is the term used to cover strategies to ensure a good night’s sleep. One of the tops tips is to try and go to bed at a regular time, before midnight. A recent study shows that is these hours before midnight that are particularly valuable for hormone health. In fact, it is useful to set an alarm for going to bed.

Another strategy to help sleep is finding a bedtime “wind down” routine that suits you. For example, reading or listening to music. Looking at mobile electronic devices is not one of these. The reason being that the light emitted from these devices prevents the production of the sleep hormone melatonin.

When it comes to hormone health, sleep is indeed the chief nourisher. Sleep and other lifestyle choices to harness hormones for optimal health, through life, are explored in detail in “Hormones, Health and Human Potential: A guide to understanding your hormones to optimise your health and performance”.

Next steps

“Hormones, Health and Human Potential: A guide to understanding your hormones to optimise your health and performance” is available in paperback and Kindle (illustrations in colour) from Amazon and direct from Sequoia books (ship overseas)

Hormone Health advisory appointments are available

Presentations and workshops

Hormones, Health and Human Potential

“Hormones, Health and Human Potential” explains how hormones play a crucial role in determining health. Hormone networks provide the feedback mechanism by which our lifestyle and behaviours enable us to reach our personal potential.

Introduction


Over 2,000 years ago Hippocrates advocated that the “safest way to health” was through “the right amount of nourishment and exercise” for “every individual”. As it turns out Hippocrates was way ahead of his time in articulating the principles of personalised and preventative medicine.

Hormones as the missing link to health


Although Hippocrates understood that lifestyle and behaviours are key to health, he did not know why. We now know that hormones are the key players in this vital role. Hormones are instigators in bringing our DNA to life by determining gene expression. Hormones direct the production of proteins, in the optimal amounts and at the right time. Hormones work as networks to maintain mental and physical health.

Lifestyle factors influencing health through hormones networks


Complex internal negative feedback loops between hormones and the biological variables that they regulate, enable homeostasis for good physiological function. Challenges to homeostasis, due to our interactions with the environment are detected by the hypothalamus, which manages hormone network response. In this way there is another layer of feedback loops between lifestyle behaviours and hormones.

Well-balance lifestyle behaviours, in terms of quantity and timing, support healthy hormone network function, leading us to the “safest way to health”. Conversely, circadian misalignment, where lifestyle choices conflict between internal biochronometers, can lead to hormone dysregulation found in conditions such as metabolic syndrome.

Harnessing hormones as preventative and supportive medicine


A good balance of lifestyle factors can harness hormones as a form of supportive and preventative medicine. This is particularly relevant for type 2 diabetes mellitus and metabolic syndrome. For women, where there are physiological changes in hormones, such as occurs at menopause, attendant symptoms and impacts on long term health can be mitigated by lifestyle as part of the management of menopause. For example, exercise has been shown to have a beneficial effect on temperature regulation, metabolism, body composition, bone health and reducing the risk of breast cancer.

Athlete performance mediated by hormones


Hormones mediate the positive adaptive changes due to exercise training. Understanding these mechanisms can benefit both athletes and patients .

Imbalances in behaviours causing hormone dysregulation


Too little exercise and excess nutrition can lead to hormone dysregulation, seen in metabolic syndrome and type 2 diabetes mellitus. On the other hand, too much of a “good thing” can also cause health and performance issues in exercisers. Relative energy deficiency in sport (RED-S) can occur in exercisers of all ages and levels, where there is either an unintentional or intentional mismatch between energy intake and energy demand. Consequent low energy availability causes hormone network disruption, which in the long-term results in adverse effects on both health and performance .

Conclusions


• Hormone network function plays an important role in mental and physical health
• Hormones are influenced by our lifestyle behaviours of exercise, nutrition and sleep
• The benefits of lifestyle behaviours are derived from the positive adaptive changes driven by hormones
• Imbalances in lifestyle behaviours can cause hormone disruption leading to adverse effects on health and exercise performance

References

Keay N. Health Hormones and Human Potential. Sequoia books. 2022

McCarthy O, Pitt J, Keay N et al Passing on the exercise baton: What can endocrine patients learn from elite athletes? Clinical Endocrinology 2022 96;(6):781-792

Keay N, Francis G Infographic. Energy availability: concept, control and consequences in relative energy deficiency in sport (RED-S) British Journal of Sports Medicine 2019;53:1310-1311.

Energy Availability: Concept, Control and Consequences in relative energy deficiency in sport (RED-S)

Relative energy deficiency in sport (RED-S) is an issue of increasing concern in sports and exercise medicine. RED-S impact exercisers of all levels and ages, particularly where low body weight confers a performance or aesthetic advantage. Key to mitigating adverse health and performance consequences of RED-S is supporting athletes and dancers to change behaviours. These infographics aim to assist clinicians in communicating the concepts to exercisers and in implementing effective management of athletes in their care[1].

Slide1

Figure 1 illustrates the concept of energy availability (EA) in RED-S. Preferentially energy derived from dietary intake covers the demands of training and the remaining energy, EA, is, quantified in Kcal/Kg of fat free mass[2]. In Figure 1, the central bar illustrates adequate EA in an athlete where energy intake is sufficient to cover the demands of training and fundamental life processes to maintain health. Conversely, low energy availability (LEA) is a situation of insufficient EA to cover basic physiological demands. LEA leads to the adverse consequences of RED-S[3]. LEA can arise unintentionally or intentionally, due to a mismatch between energy intake and energy requirement. In Figure 1 the bar on the left shows LEA resulting from reduced energy intake with maintained training load. On the right, LEA is a consequence of increased training load with maintained energy intake.

Figure 2 illustrates that EA is under the control of an athlete[4]. The three behaviours relating to training, nutrition and recovery determine EA. Integrated periodisation of these behaviours results in optimal health and performance. Conversely, an imbalance in these behaviours results in suboptimal functionally. LEA in the case of high training loads relative to nutritional intake. Thus, this figure reinforces the important point in the IOC statements on RED-S that psychological factors which determine these behaviours are key in both the development, continuation and management of RED-S[2,3].

Slide1

Figure 2 also shows the temporal, synergistic effect of these behaviours to ensure a fully functioning endocrine system. Hormones are key for health and to drive positive adaptations to exercise, to improve athletic performance. Thus hormones can be informative in tracking the response of an individual to these three input variables. Furthermore, endocrine markers relate to the RED-S clinical outcome of stress fracture in athletes, being more reliable as objective, quantifiable indicators of EA than numerical calculation of EA from direct assessment[5].

Authors

Nicola Keay1, Gavin Francis2

1 Department of Sport and Exercise Sciences, Durham University

2 Science4Perforamnce, London

Br J Sports Med 2019;0:1–2. doi:10.1136/bjsports-2019-100611

References

1 http://health4performance.co.uk (accessed 21/01/2019) Health4Performance Educational BASEM website raising awareness of RED-S Working group on RED-S British Association of Sport and Exercise Medicine 2018

2 Mountjoy M, Sundgot-Borgen J, Burke L et al. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update Br J Sports Med2018;52(11):687-697

3 Mountjoy M, Sundgot-Borgen J, Burke L et al. The IOC consensus statement: beyond the Female Athlete Triad–Relative Energy Deficiency in Sport (RED-S). Br J Sports Med2014;48(7):491-7

4 Burke L, Lundy B, Fahrenholtz L et al, & Melin. Pitfalls of conducting and interpreting estimates of energy availability in free-living athletes. International Journal of Sport Nutrition and Exercise Metabolism2018; 28(4):350–363. https://doi.org/10.1123/ijsnem.2018-0142

5 2Heikura I, Uusitalo A, Stellingwerff T et al. Low energy availability is difficult to assess but outcomes have large impact on bone injury rates in elite distance athletes. International Journal of Sport Nutrition and Exercise Metabolism2018; 28(4):403–411. https://doi.org/10.1123/ijsnem.2017-0313

Returning to Sport/Dance restoring Energy Availability in RED-S?

Although improvements are being made in raising awareness and in effective medical management of relative energy deficiency in sport (RED-S)[1, 2] what about once an athlete/dancer is “medically cleared” to return to sport/dance? What advice/support is there for athletes/dancers and their coaches/teachers? After discussions with coaches, here are some suggestions on how to achieve return to sport/dance after RED-S.

LifeSeasonDayTo recap, RED-S is a situation of low energy availability (LEA), which can lead to adverse health and performance consequences[3,4]. LEA can be a result of intentional energy restriction, which covers a spectrum of issues with eating from disordered eating to full blown clinical eating disorder. Ironically the original intention of these eating issues may have been to improve athletic performance, yet sustained LEA will ultimately lead to stagnation and deterioration in performance as found in male athletes[5].

The desire to return to full fitness can be a powerful incentive to address LEA. Nevertheless return to sport/dance needs to be carefully structured in collaboration with coaches to prevent injury and avoiding regression to the LEA state.

Structured return to training and nutrition

  • Initially focus should be on body weight strength and conditioning (S&C). Inevitably in RED-S adaptive responses to training stimuli will be dampened due to shut down of hormones networks into an energy saving mode. Once adequate EA has been established, hormone networks will be able to respond. Restoring muscle tone and working on proprioception forms a good basis to build from to mitigate injury risk. Impaired neuromuscular skills have been reported in female athletes in LEA[6], together with adverse effects of LEA on bone health increases injury risk.
  • The other reason for gradual return to training is that a routine of fuelling around training (before, during, after) needs to be established. In particular recovery nutrition within 30 minutes window to enable hormonal responses to training. Note that having this recovery nutrition does not mean reducing intake at the next meal!
  • Long endurance should be eased into after restoring muscle strength and control, in order to prevent injury. Additionally this type of training will necessitate a higher energy requirement. If adequate energy availability has only recently been restored, the balance is fragile and so too much training too soon can have negative effects. Especially if a fuelling strategy around training has not been established as described above.
  • High intensity/interval training should be the last type of training to be resumed as this places the highest stress and requires the highest energy demand on the athlete/dancer.
  • Injury, soft tissue and bone stress responses are more frequent in hormonal dysfunction of RED-S in both male and female athletes[7]. If an injury has been sustained during this period of LEA then particular emphasis needs to be on initial S&C. In the case of previous bone stress responses, multi-direction loading is key to build bone strength before resuming formal run training in athletes who are runners. Even if a bone injury has not occurred, bone turnover is one of the first systems to be adversely impacted by RED-S, so including this type of multidirectional bone loading in the initial structured return for all athletes/dancers would be beneficial.
  • Discuss with your coach a realistic, attainable goal if this will help. Maybe a low key race/event several months down the track

What to look out for

  • Don’t ignore injury niggles, illness or fatigue. Discuss with your coach and back off if necessary. This is a process, not a sprint.
  • Female athletes. You may well have experienced menstrual disruption during your time in LEA. This is a crucial training metric. Please use it! If your menstruation becomes irregular/stops this is your warning sign that your body is not ready to step up training[7]. Male coaches please reinforce this and be aware of this point. Remember Gwen Jorgensen posting her periods on Training Peaks as a training metric?
  • Flexibility in approach. Try not to put pressure on yourself to return to your previous PBs. It is important to have a plan, but you can be flexible. Everyone is different so this process of returning to sport/dance does not have a set, rigid timetable.
  • Enjoyment! Don’t forget the original reason that you started your sport/dance was for enjoyment! This is an opportunity to rediscover that joy, whether you return to competition or not.
  • “Recovery?” Does anyone fully “recover” from disordered eating/eating disorder? I don’t think so. To be a successful athlete, or indeed successful in life you need self-motivation, drive, determination. All admirable qualities, but sometimes these can get diverted to cause unhealthy eating/training patterns. So be aware that in times of stress it may be tempting to revert to old habits of under eating/over exercise to reassure yourself that you are in control.
  • Be prepared for questions: why have you been off training? Why are you not doing fully training schedule? Maybe you want to tell your team mates/friends. Maybe you don’t. That is your call.

So good luck with your return to sport/dance after RED-S, if that is what you want to do. Always discuss with you coach how to approach this.

References

1 BASEM Educational website www.health4perforamnce.co.uk

BJSM blog: Update on RED-S N Keay 2018

3, 4 IOC consensus statements on RED-S BJSM 2014 and update 2018

5 Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists. N Keay, G Francis, K Hind. BMJ Open in Sport and Exercise Medicine 2018

5 Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes.
Tornberg Å Melin A Koivula F Johansson A Skouby S et. al.Medicine and science in sports and exercise 2017 vol: 49 (12) pp: 2478-2485

6 Low Energy Availability Is Difficult to Assess but Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes Heikura, Ida A. Uusitalo, Arja L.T. Stellingwerff, Trent et al International Journal of Sport Nutrition and Exercise Metabolism 2018, 28, 4, 403-411

7 What’s so good about Menstrual Cycles? N Keay BJSM blog 2019

What’s so good about menstrual cycles?

Menstrual periods are a barometer of healthy hormones. The evolutionary purpose of ovulation is to reproduce. Furthermore the carefully biologically choreographed variation of hormones that occurs during an ovulatory menstrual cycle is crucial to health and athletic performance.

Why? Hormones are chemical messengers that have far reaching effects throughout the body and drive the beneficial adaptations to exercise. In the case of menstrual cycles, the fluctuations of oestrogen and progesterone are key to this process. The effects of these sex steroids go far beyond reproduction. These hormones play important roles in bone strength, cardiovascular health, optimal lipid profile and production of neurotransmitters to regulate mood. The effects of low levels of oestrogen and progesterone are well documented in menopausal women who experience loss in bone mass, risk of osteoporosis and fracture, together with an increase risk of cardiovascular disease.

Some definitions

Amenorrhoea=lack of menstrual cycles

Menarche= start of menstrual cycles

According to the Royal College of Obstetrics and Gynaecology

Primary Amenorrhoea: no onset of menstrual cycles by age 16 years.

Secondary amenorrhoea: cessation of menstrual cycles in a previously regularly menstruating woman for > 6months

Oligomenorrhoea: < 9 menstrual cycles per calendar year

Any form of amenorrhoea requires medical investigation to exclude an underlying medical condition. The most common medical causes of amenorrhoea are polycystic ovary syndrome (PCOS), prolactinoma, thyroid conditions and other endocrine conditions. Functional hypothalamic amenorrhoea (FHA) is a diagnosis of exclusion. In other words before arriving at a diagnosis of FHA [1], medical conditions that could potentially cause amenorrhoea have to be ruled out.

Screen Shot 2019-01-30 at 12.09.28

Relative energy deficiency in sport (RED-S) is a situation of low energy availability (LEA) that can be unintentional or intentional as a result of a mismatch between energy intake and energy requirement. The two sources of energy demand arise from exercise training load and maintenance of fundamental physiological function across multiple body systems [2]. In female athletes/dancers with RED-S the most obvious clinical sign is amenorrhoea as a result of FHA. In all cases of RED-S the management strategy is directed to address the underlying issue of LEA [3].

In female athletes/dancer with FHA due to RED-S, there is the possibility of pharmacological intervention based on the RED-S Clinical Assessment Tool [4]. In other words evidence from DXA of Z-score of lumbar spine < -1 and/or stress fracture. What are the most effect hormonal interventions in such cases?

What’s in a name? It is every woman’s right to choose the form of contraception she wishes to use. Hormonal contraception provides a convenient method. The combined oral contraceptive pill (OCP) contains oestrogen and progesterone to prevent ovulation. The OCP produces regular withdrawal bleeds in response to these external hormones. Progesterone-only contraception can be taken orally, via implant or delivered by an intrauterine coil and typically does not produce withdrawal bleeds. As with any medication there are potential side effects, which have to be weighed up against the benefits. Regarding the effect of hormonal contraception on bone in young menstruating women, there is evidence that such medication can impair bone health [5].

The OCP produces regular withdrawal bleeds. These are NOT menstrual periods; ovulation is prevented. Rather the OCP causes withdrawal bleeds driven by external non-physiological hormones, as opposed to internally physiologically produced hormones. This is a reason why the OCP is not recommended in FHA, as this medication will mask what is happening with internal hormones [6]. In other words the barometer of healthy hormones has been removed when taking the OCP.

Furthermore, studies show that the OCP can impact other hormone systems that play a role in bone health. The OCP is taken orally thereby producing first pass effects in the liver. These effects include induction of liver enzymes and increased production of binding proteins for hormones. Binding proteins reduce the freely available active form of hormones such insulin like growth factor 1 (IGF-1). This effect is particularly marked in those OCP with non-physiological ethinyl oestradiol. In the case of RED-S there is already a low level of active IFG-1, due to the general suppression of the hypothalamic-pituitary axis.

Therefore in addition to masking FHA, the OCP can also further decrease IGF-1 and thus compound the negative effect on bone. This has been shown to be the case in the clinical setting where the OCP was found to have no bone protective effect on bone mineral density (BMD) in women with FHA. Rather hormone replacement therapy (HRT) consisting of transdermal physiological oestrogen with cyclic micro-ionised progesterone was found to have a positive effect on BMD [7 , 8]

Therefore, if hormonal treatment is to be used in RED-S, HRT (transdermal oestradiol and cyclic micro-ionised progesterone) is best clinical practice. This decision requires careful discussion with the athlete/dancer clarifying that HRT should only be a short-term measure to protect bone health whilst the underlying issue of LEA is being resolved. Behavioural measures relating to training load, nutrition and recovery are essential to restore global hormonal function.

OCP V HRT

• What? Both provide oestrogen and progesterone, but in different forms: non-physiological v physiological

Why? Purpose of the OCP is to suppress production of endogenous female hormones and prevent ovulation. Purpose of HRT is to replace the physiological amount and form of oestrogen and progesterone

How? The OCP decreases levels of active, unbound IGF-1. Not bone protective in FHA of RED-S. HRT shown to improve BMD in FHA of RED-S

What to do? Hormonal contraception is a choice for women. In some medical conditions where there is adequate/excess oestrogen such as endometriosis or PCOS, hormonal contraception is effective in clinical management. However in the case of FHA, in particular when occurring as a consequence of LEA in RED-S there is evidence that the OCP is not bone protective and masks the clinical sign of menstruation.

The priority in managing RED-S is to address LEA. If bone protection is required, whilst addressing LEA, HRT (transdermal oestrogen and cyclic progesterone) is best clinical practice.

References

[1] Joy, E., De Souza, M. J., Nattiv, A., Misra, M., Williams, N. I., Mallinson, R. J., … Borgen, J. S. (2014). 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad. Current Sports Medicine Reports, 13(4), 219–232. https://doi.org/10.1249/JSR.0000000000000077

[2] Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., … Ljungqvist, A. (2014). The IOC consensus statement: Beyond the Female Athlete Triad-Relative Energy Deficiency in Sport (RED-S). British Journal of Sports Medicine48(7), 491–497. https://doi.org/10.1136/bjsports-2014-093502

[3] Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N., … Budgett, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine, 52(11), 687–697. https://doi.org/10.1136/bjsports-2018-099193

[4] Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., … Ackerman, K. (2015, April 1). Relative energy deficiency in sport (RED-S) clinical assessment tool (CAT). British Journal of Sports Medicine. BMJ Publishing Group. https://doi.org/10.1136/bjsports-2015-094873

[5] Beksinska M, Smit J, Hormonal contraception and bone mineral density. Expert Review of Obstetrics & Gynecology, 2011 vol: 6 (3) pp: 305-319

[6] Gordon, C. M., Ackerman, K. E., Berga, S. L., Kaplan, J. R., Mastorakos, G., Misra, M., … Warren, M. P. (2017). Functional hypothalamic amenorrhea: An endocrine society clinical practice guideline. Journal of Clinical Endocrinology and Metabolism102(5), 1413–1439. https://doi.org/10.1210/jc.2017-00131

[7] Ackerman, K. E., Singhal, V., Baskaran, C., Slattery, M., Campoverde Reyes, K. J., Toth, A., … Misra, M. (2018). Oestrogen replacement improves bone mineral density in oligo-amenorrhoeic athletes: A randomised clinical trial. British Journal of Sports Medicine. BMJ Publishing Group. https://doi.org/10.1136/bjsports-2018-099723

[8] Singhal, V., Ackerman, K. E., Bose, A., Torre Flores, L. P., Lee, H., & Misra, M. (2018). Impact of Route of Estrogen Administration on Bone Turnover Markers in Oligoamenorrheic Athletes and its Mediators. The Journal of Clinical Endocrinology & Metabolism. https://doi.org/10.1210/jc.2018-02143

 

 

Low Energy Availability in Climbers

Listen into a great discussion I had with Dr Nigel Callender an ex competitive climber and climbing coach about the “elephant in the room” in competitive climbing.

Discussion of Low Energy Availability and RED-S

As a gravitational sport, being a light-weight climber confers a performance advantage. However, being alert to low energy availability and the clinical consequences of RED-S on health and performance is important for climbers. With climbing being included the next Olympics, then hopefully this will raise awareness of being alert to athletes at risk of low energy availability and RED-S.

IMG_0175

Insights from Dr Nigel Callender, sports scientist turned medical doctor (anaesthetics/critical care trainee) an active researcher, largely into the exercise physiology aspects of climbing and ex-competitor, having represented Ireland at international level and been British bouldering champion before shoulder injuries ended that. Sport climbing is included in the 2020 Tokyo summer games in its three competitive disciplines; bouldering, lead climbing and speed climbing. Each sub-discipline has a slightly different athlete profile and physiological demands, but all are obviously under the heading of gravity dependent sports. Current participation figures put yearly indoor climbing participation at around the one million mark in the UK and it is said to be one of the fastest growing sports worldwide. The sport is being recognised as a great way to improve overall health and fitness, with recent papers citing it as a useful rehab activity for many physical and mental health conditions and also as a health promotion tool.

Although climbing has been a formal competitive sport in some sense since the late 80’s, it still lacks much in the way of formal training and medical guidelines. Being a gravity dependent sport, strength to weight ratio is important, however Dr Callender and his colleagues are seeing a high incidence of restrictive eating patterns at all levels of the sport and a lack of awareness around the performance impairments and health risks associated with a significant or prolonged negative energy balance in some athletes.

The Outdoor Athlete Podcast is a bit of a winter project that came about to establish a gold-standard resource, driven by credible experts in their relevant fields, as an attempt to provide high-quality and evidence-based information amongst the confusing advice that is now the internet. It’s free and always will be and it was inspired by the BJSM Podcasts though broadly aiming at ‘Outdoor Athletes’ e.g. Climbers, Fell/Trail runners, Mountain bikers and anyone happy to listen.

For more information on climbing in the UK, including competition climbing see http://www.thebmc.co.uk

Raising Awareness of RED-S in Male and Female Athletes and Dancers

Health4Performance is a recently developed BASEM open access educational resource

This is a world premier: a resource developed for and by athletes/dancers, coaches/teachers, parents/friends and healthcare professionals to raise awareness of Relative Energy Deficiency in Sport (RED-S)

What?

Optimal health is required to attain full athletic potential. Low energy availability (LEA) can compromise health and therefore impair athletic performance as described in the RED-S clinical model.

Dietary energy intake needs to be sufficient to cover the energy demands of both exercise training and fundamental physiological function required to maintain health. Once the energy demands for training have been covered, the energy left for baseline “housekeeping” physiological function is referred to as energy availability (EA). EA is expressed relative to fat free mass (FFM) in KCal/Kg FFM.  The exact value of EA to maintain health will vary between genders and individuals, roughly equivalent to resting metabolic rate of the individual athlete/dancer. LEA for an athlete or dancer will result in the body going into “energy saving mode” which has knock on effects for many interrelated body systems, including readjustment to lower the resting metabolic rate in the longer term. So although loss in body weight may be an initial sign, body weight can be steady in chronic LEA due to physiological energy conservation adaptations. Homeostasis through internal biological feedback loops in action.

The most obvious clinical sign of this state of LEA in women is cessation of menstruation (amenorrhea). LEA as a cause of amenorrhoea is an example of functional hypothalamic amenorrhoea (FHA). In other words, amenorrhoea arising as a result of an imbalance in training load and nutrition, rather than an underlying medical condition per se, which should be excluded before arriving at a diagnosis of FHA. All women of reproductive age, however much exercise is being undertaken, should have regular menstrual cycles, which is indicative of healthy hormones. This explains why LEA was first described as the underlying aetiology of the female athlete triad, as women in LEA display an obvious clinical sign of menstrual disruption. The female athlete triad is a clinical spectrum describing varying degrees of menstrual dysfunction, disordered nutrition and bone mineral density. However it became apparent that the clinical outcomes of LEA are not limited to females, nor female reproductive function and bone health in female exercisers. Hence the evolution of the clinical model of RED-S to describe the consequences of LEA on a broader range of body systems and including male athletes.

A situation of LEA in athletes and dancers can arise unintentionally or intentionally. In the diagram below the central column shows that an athlete where energy intake is sufficient to cover the demands from training and to cover basic physiological function. However in the column on the left, although training load has remained constant, nutritional intake has been reduced. This reduction of energy intake could be an intentional strategy to reduce body weight or change body composition in weight sensitive sports and dance.  On the other hand in the column on the right, training load and hence energy demand to cover this has increased, but has not been matched by an increase in dietary intake. In both these situations, whether unintentional or intentional, the net results is LEA, insufficient to maintain health. This situation of LEA will also ultimately impact on athletic performance as optimal health is necessary to realise full athletic potential.

Slide1

Although LEA is the underlying aetiology of RED-S, there are many methodological and financial issues measuring LEA accurately in “free living athletes“. In any case, the physiological response varies between individuals and depends on the magnitude, duration and timing of LEA. Therefore it is more informative to measure the functional responses of an individual to LEA, rather than the value calculated for EA. As such, Endocrine markers provide objective and quantifiable measures of physiological responses to EA. These markers also reflect the temporal dimension of LEA; whether acute or chronic. In short, as hormones exert network effects, Endocrine markers reflect the response of multiple systems in an individual to LEA. So by measuring these key markers, alongside taking a sport specific medical history, provides the information to build a detailed picture of EA for the individual, with dimensions of time and magnitude of LEA. This information empowers the athlete/dancer to modify the 3 key factors under their control of training load, nutrition and recovery to optimise their health and athletic performance.

Slide1

Why?

Who is at risk of developing RED-S? Any athlete involved in sports or dance where being light weight confers a performance or aesthetic advantage. This is not restricted to elite athletes and dancers. Indeed the aspiring amateur or exerciser could be more at risk, without the benefit of a support team present at professional level. Young athletes are at particular risk during an already high energy demand state of growth and development. Therefore early identification of athletes and dancers at risk of LEA is key to prevention of development of the health and performance consequences outlined in the RED-S clinical model. Although there is a questionnaire available for screening for female athletes at risk of LEA, more research is emerging for effective and practical methods which are sport specific and include male athletes.

How?

Early medical input is important as RED-S is diagnosis of exclusion. In other words medical conditions per se need to be ruled out before arriving at a diagnosis of RED-S.  Prompt medical review is often dependent on other healthcare professionals, fellow athletes/dancers, coaches/teachers and parents/friends all being aware and therefore alert to RED-S. With this in mind, the Health4Performance website has areas for all of those potentially involved,  with tailored comments on What to look out for? What to do? Ultimately a team approach and collaboration between all these groups is important. Not only in identification of those at risk of LEA, but in an integrated support network for the athlete/dancer to return to optimal health and performance.

References

Heath4Performance BASEM Educational Resource

Video introduction to Health4Performance website

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

What is Dance Medicine? BJSM 2018

Identification and management of RED-S Podcast 2018

Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists Keay, Francis, Hind. BJM Open Sport and Exercise Medicine 2018

How to Identify Male Cyclists at Risk of RED-S? 2018

Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes IJSNM 2018

Low Energy Availability Is Difficult to Assess but Outcomes Have Large Impact on Bone Injury Rates in Elite Distance Athletes IJSNM 2017

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

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

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

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

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

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

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

Sam

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

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

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

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

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

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

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

References 

Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists  Keay, Francis, Hind, BMJ Open in Sport and Exercise Medicine 2018

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

Fuelling for Cycling Performance Science4Performance

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

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

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

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

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

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

Cyclists: Make No Bones About It Keay, BJSM 2018

Male Athletes: the Bare Bones of Cyclists

Cyclists: How to Support Bone Health?

Synergistic interactions of steroid hormones Keay BJSM 2018

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

 

What is Dance Medicine?

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

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

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

BalletDials
Integrated periodisation of training, nutrition and recovery support perforamnce

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

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

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

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

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

References

Presentations

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

Fit to Dance 2 Dance UK

One Dance

Your body your risk. Dance UK

Fit but fragile. National Osteoporosis Society

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

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

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

Dancing through Adolescence Dr N Keay BJSM

Healthy Hormones Dr N Keay BASEM 2018

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

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

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

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

 

 

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

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

Prevention

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

Identification

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

Performance effects

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

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

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

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

REDs
Keay BJSM 2017

Medical Assessment

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

 

Management

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

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

What next?

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

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

References

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

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

Male Athletes: the Bare Bones of Cyclists

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

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

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

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

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

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

Cyclists: Make No Bones About It BJSM 2018

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

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

Cyclists: How to Support Bone Health?

Healthy Hormones BASEM 2018