Tag: adaptation to exercise

Clusters of Athletes

2 April 2017

 At some time, most athletes experience periods of underperformance. What are the potential causes and contributing factors?

classification

Effective training improves sports performance through a process of adaptation that occurs, at both the cellular and system levels, during the recovery phase. Training overload must be balanced with sufficient subsequent recovery. A long-term improvement in form is expected, following a temporary dip in performance, due to short-term fatigue.

However, when an athlete experiences a stagnation of performance, what are the potential underlying causes? How should these be addressed to prevent an acute situation developing into a more chronic spiral of decreasing performance?

Depending on clinical presentation, the first step is to exclude medical conditions. Potential infective causes include Epstein Barr virus (particularly in young athletes), Lyme disease and Weil’s disease. Systemic inflammatory conditions should be considered. Endocrine and metabolic causes include pituitary, gonadal, adrenal, thyroid  dysfunction, blood sugar control,  and malabsorption.

If medical conditions are excluded, attention should turn to the athlete’s energy balance in the context of adherence to the current training plan. Potential causes of underperformance, the inability to improve in training and competition, are illustrated in the diagram above.

Athletes in the upper right quadrant fail to live up to performance expectations, in spite of maintaining a good energy balance while adhering to the prescribed training plan. However, they may represent non-functional overreaching, where overload is not balanced with sufficient recovery. In other words, the periodisation of training and recovery is not optimised. The balance between chronic training load (fitness) and acute training load (fatigue) provides a useful metric for assessing form. Heart rate variability (HRV) can be another potentially useful measure in detecting aerobic, endurance fatigue. If the training plan is not producing the expected improvements, then this plan needs revising. Don’t forget that sleep is essential to facilitate endocrine driven adaptations to exercise training.

Athletes in the lower right quadrant are of more concern. Inadequate energy balance, especially during periods of increased training load or intentional weight loss, can be a cause of underperformance, despite the athlete being able to adhere to the training plan. This would correspond to being at risk of developing relative energy deficiency in sport (RED-S) on the amber warning in the risk stratification laid out by the International Olympic Committee.

Both of these groups are able to adhere to a training plan, but suboptimal training and recovery periodisation and/or insufficient energy intake can produce a situation of underperformance. Intervention is required to prevent them moving into the clusters on the left, representing a more chronic underperformance scenarios that are therefore more difficult to rectify.

Athletes in the upper left quadrant exhibit overtraining syndrome: a prolonged maladaptation process accompanied by a decrease in performance (not merely stagnation) and inability to adhere to training plan. The metric of decreased HRV and inability of heart rate to accelerate in response to exercise have been suggested as markers of overtraining.

Those athletes in the lower left quadrant fall into the RED-S category, where multiple interacting Endocrine networks are impacted by an energy deficient state. RED-S not only impairs sports performance, but impacts both current and future health. For example low endogenous levels of sex steroids and insulin-like growth factor 1 (IGF1) disrupt formation of bone microarchitecture and bone mineralisation, resulting in increased risk of recurrent stress fracture in addition to potentially irreversible bone loss in the longer term. In cases of recurrent injury and underperformance amongst athletes it is imperative to exclude Endocrine dysfunction and then consider whether RED-S is the fundamental cause.

There are many potential causes of underperformance in athletes. Once medical conditions have been excluded, the main aim should be to prevent acute situations becoming chronic and therefore more difficult to resolve.

For further discussion on Endocrine and Metabolic aspects of SEM come to the BASEM annual conference 22/3/18: Health, Hormones and Human Performance

References

Sport Endocrinology Dr N. Keay, British Journal of Sport Medicine 2017

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

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

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

Balance of recovery and adaptation for sports performance Dr N. Keay, British Association of Sport and Exercise Medicine

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

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

Inflammation: why and how much? Dr N. Keay, British Association of Sport and Exercise Medicine

Fatigue, Sport Performance and Hormones… Dr N.Keay, British Journal of Sport Medicine

Part 3: Training Stress Balance—So What? Joe Friel

Heart Rate Variability (HRV) Science for Sport

Relative Energy Deficiency in sport (REDs) Lecture by Professor Jorum Sundgot-Borgen, IOC working group on female athlete triad and IOC working group on body composition, health and performance. BAEM Spring Conference 2015.

Prevention, Diagnosis, and Treatment of the Overtraining Syndrome: Joint Consensus Statement of the European College of Sport Science and the American College of
Sports Medicine. Joint Consensus Statement. Medicine & Science in Sports & Exercise 2012

Sleep for Health and Sports Performance

22 December 2016

“Sleep.. chief nourisher in life’s feast,” Macbeth.

In my blog for British Association of Sport and Exercise Medicine, I described improving sport performance by balancing the adaptive changes induced by training together with the recovery strategies to facilitate this, both in the short and long term.  alec0120-12x17

A recovery strategy which is vital in supporting both health and sport performance, during all stages of the training cycle is sleep.

Sufficient sleep is especially important in young athletes for growth and development and in order to support adaptive changes stimulated by training and to prevent injury. Amongst teenage athletes, studies have shown that a lack of sleep is associated with higher incidence of injury. This may be partly due to impaired proprioception associated with reduced sleep. Sleep is vital for consolidating neurological function and protein synthesis, for example in skeletal muscle. Sleep and exercise are both stimuli for growth hormone release from the anterior pituitary, which mediates some of these adaptive effects.

Lack of sleep can also interfere with functioning of the immune system due to disruption of the circadian rhythm of secretion in key areas of the Endocrine system. Athletes in heavy training, with high “stress” loads and associated elevated cortisol can also experience functional immunosuppression. So a combination of high training load and insufficient sleep can compound to disrupt efficient functioning of the immune system and render athletes more susceptible to illness and so inability to train, adapt and recover effectively.  Lack of sleep disrupts carbohydrate metabolism and recently found to suppress expression of genes regulating cholesterol transport. In overreaching training, lack of sleep could be either a cause or a symptom of insufficient recovery. Certainly sleep deprivation impairs exercise performance capacity (especially aerobic exercise) although whether this is due to a psychological, physical or combination effect is not certain.

Sufficient sleep quality and quantity is required for cognitive function, motor learning, and memory consolidation. All skills that are important for sports performance, especially in young people where there is greater degree of neuroplasticity with potential to develop neuromuscular skills. In a fascinating recorded lecture delivered by Professor Jim Horne at the Royal Society of Medicine, the effects of prolonged wakefulness were described. Apart from slowing reaction time, the executive function of the prefrontal cortex involved in critical decision making is impaired. Important consequences not only for athletes, but for doctors, especially for those of us familiar with the on call system in hospitals back in the bad old days. Sleep pattern pre and post concussive events in teenage athletes is found to be related to degree and duration of concussive symptoms post injury. The explanation of how sleep deprivation can cause these functional effects on the brain has been suggested in a study where subtle changes in cerebral neuronal structural properties were recorded. It is not known whether these changes have long term effects.

So given that sleep is essential not only for health and fitness, but to support sports performance, what strategies to maximise this vital recovery process? Use of electronic devices shortly before bedtime suppresses secretion of melatonin (neurotransmitter and hormone), which is a situation not conducive for sleep. Tryptophan is an amino acid precursor in the synthesis of melatonin and serotonin (neurotransmitter) both of which promote sleep. Recent research demonstrates that protein intake before bed can support skeletal and muscle adaptation from exercise and also recovery from tendon injury. Conversely there is recent report that low levels of serotonin synthesis may contribute to the pathogenesis of autoimmune inflammatory disease such as rheumatoid arthritis. This highlights the subtle balance between degree of change required for positive adaptation and a negative over-response, as in inflammatory conditions. This balance is different for each individual, depending on the clinical setting. So maybe time to revisit the warm milky drink before bed? Like any recovery strategy, sleep can also be periodised to support exercise training, with well structured napping during the day as described by Dr Hannah Macleod, member of gold winning Olympic Hockey team.

In conclusion, when you are planning your training cycle, don’t forget that periodised recovery to compliment your schedule should be factored in, with sleep a priority recovery and adaptation strategy.

For further discussion on Endocrine and Metabolic aspects of SEM come to the BASEM annual conference 22/3/18: Health, Hormones and Human Performance

References

Balance of recovery and adaptation for sports performance Dr N. Keay, British Association of Sport and Exercise Medicine

Sleep, Injury and Performance

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

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

Sleep and sporting performance

Young people: neuromuscular skills for sports performance

Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses

“Sleepiness and critical decision making”. Recorded lecture Professor Jim Horne, Royal Society of Medicine 16/11/16

What Does Sleep Deprivation Actually Do To The Brain?

Pre-Sleep Protein Ingestion to Improve the Skeletal Muscle Adaptive Response to Exercise Training

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

Serotonin Synthesis Enzyme Lack Linked With Rheumatoid Arthritis

“Science in Elite Sport” Dr Hannah Macleod, University of Roehampton, 6/12/16

Balance of Recovery and Adaptation for Sport Performance

11 December 2016

There has been much recent discussion about the optimal balance of recovery strategies to enable effective return to training, and adaptive processes which occur as the result of training to improve sporting performance.

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I have been reading the scientific reports to try and gain an understanding of this balance between recovery and adaptation. However, my investigations were put into context after attending two fascinating meetings last week where insightful talks were given by Dr Hannah Macleod Olympic gold medallist and presentations at the King’s Sport and Exercise Medicine Conference.

The scientific principle behind exercise training, of any sort, is that improvement in exercise performance follows from the cycle of overload exercise, followed by recovery phase during which adaptive changes occur in musculoskeletal, cardiovascular, metabolic and neurological systems to improve exercise performance capacity. If sufficient recovery is not taken before next training session, then rather than a progressive stepwise upward improvement in performance capacity, a downward progression occurs. In order to avoid this overreaching and overtraining scenario, rather to improve performance, training cycle as described by Dr Macleod often consists of 3 weeks “on”, followed by “rest” week together with well structured napping.

Theoretically, if the amount of recovery needed could be shortened, then more training could be done and thus potentially more adaptive advantages gained. However, by shortening recovery time with various strategies, this might actually curtail and reduce the very adaptive changes being sought. Considering recovery and adaptive responses of skeletal muscle to exercise, there are recent apparently contradictory reports on the benefits of ice baths. To ice bath or not to? Certainly for muscle injury RICE (rest, ice, compression, elevation) regime is well established. Does the same apply for skeletal muscle recovery and adaptation post exercise? The most recent study on 9 non-elite athletic males revealed that post resistance exercise there was no difference in the inflammatory markers or cellular stress markers in skeletal muscle whether recovery was either active or with cold water immersion. Nevertheless a previous study 2015 by the same group had reported attenuated gains in muscle mass and strength with cold water immersion recovery during 3 months of resistance training in 24 non-elite athletic males. The main issue seems to be that it all depends on the part of the long term training cycle and the type of sport in which the athlete is involved. For example, during pre-season training, where long term adaptations are being sought, then an ice bath might potentially attenuate adaptive responses gained from strength training. On the other hand, in the acute clinical setting, post match in a multi-day competition, an ice bath may be of benefit during the course of this competition period. Certainly Dr Macleod described having a compressive ice system on the team bus post match during the Olympics in Rio where 8 matches were played over 14 days. So recovery, especially from any impact injuries, was far more important than considerations of longer term performance in resistance training post Olympics. Not to mention the psychological beneficial effect to athletes with reduced perception of fatigue and muscle soreness and feeling in control of all factors possible.

Finally I would also suggest that just as there is variation between individuals in the positive adaptive responses to exercise, probably genetically determined, there may also be individual variation in the extent and benefits of recovery strategies. For example, in a clinical setting, an over-response of the inflammatory pathways can actually cause harm, such as in autoimmune disease. Another point is that I have restricted this blog to discuss cellular responses of skeletal muscle to resistance exercise and competition. Clearly there are other mechanisms involved in exercise training adaptations such as the neuroendocrine system, together with other types of exercise training and other recovery strategies.

In conclusion, just as training is periodised, it would appear that recovery strategies should also be periodised in conjunction with the phase of the training /competition cycle and type of sport. Apart from the scientific rational, the psychological aspects for athletes also has to be considered.

For further discussion on Endocrine and Metabolic aspects of SEM come to the BASEM annual conference 22/3/18: Health, Hormones and Human Performance

References

“Science in Elite Sport” talk by Dr Hannah Macleod at University of Roehampton 6/12/16

“Assessing the field of play” King’s Sport and Exercise Medicine Conference, Guy’s Hospital 5/12/16

Inflammation: why and how much? Dr N. Keay, British Association of Sport and exercise Medicine 2017

Endocrine system: balance and interplay in response to exercise training

Rapid recovery versus long term adaptation

Cold water therapy and bad journalism

Do post-work out ice bath help with recovery of sore muscles?

The Use of Cryotherapy in Sports Injuries

The effects of cold water immersion and active recovery on inflammation and cell stress responses in human skeletal muscle after resistance exercise

Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training

Ice baths for recovery-black, white or somewhere in between?