Dr. Robin Thorpe spent the last decade working as a senior performance scientist and conditioning coach at Manchester United Football Club of the English Premier League. He worked with the first team delivering performance and conditioning support to players while overseeing and managing fatigue, recovery, and regeneration practices throughout the club as Head of Recovery and Regeneration.
Dr. Thorpe completed an applied Ph.D. with Liverpool John Moores University investigating methods of fatigue and performance monitoring, which has led to a number of original articles published in peer-reviewed journals. Much of his work to date has centered around a model of monitoring the player response to stress in order to maximize athlete availability, training load prescription, and recovery and reduce injury and illness risk. Dr. Thorpe also holds the position of Visiting Research Fellow at Liverpool John Moores University.
He has worked with many high-profile athletes and assisted in the preparation of the Mexican national football team leading up to the 2018 FIFA World Cup. In May of this year, Dr. Thorpe accepted a position as Director of Performance & Innovation at ALTIS, working with elite track and field athletes in the lead-up to the Olympic Games (Tokyo 2020). As part of his role, he serves as the Director of the ALTIS LIVING LAB, which integrates applied and academic sports performance research in the field to push the boundaries of sports innovation science and knowledge to athletes, coaches, and the industry as a whole.
Freelap USA: Recovery is a wide topic today, and many coaches are afraid for athletes to get tired. When is it okay for athletes to be fatigued, and how does this encourage positive adaptations? It’s important to be fresh for quality sessions, but sometimes you have to push through fatigue. Can you give some pointers on when it’s okay to train through fatigue?
Robin Thorpe: Professionalism in sport has provided the foundation for elite athletes to focus purely on training and competition. Furthermore, high-performance sport and the importance of athletes’ success have led athletes and coaches alike to continually seek any advantage or edge that may improve performance. Enhancing recovery through training and performance may provide numerous benefits during repetitive high-level training and competition, and the rate and quality of recovery in the high-performance athlete may be as important as the training itself.
Nevertheless, there are other factors that coaches should consider. During periods of high training loads and intensive competition, the first thing they often do is attempt to minimize the resultant fatigue and enhance recovery. However, there will be times during a season/pre-season when this initial perspective may not be optimal for overall performance, and there will certainly be times where this approach may diminish some positive physiological adaptations.There are times when minimizing fatigue and enhancing recovery may not be optimal for an athlete’s overall performance and may even diminish some positive physiological adaptations. Click To Tweet
An important consideration during a large proportion of the training and competition season is whether to maximize recovery or adaptation. Pre-season and often the initial phase of the competition season (team sports) are periods when coaches/practitioners periodize load aimed at maximizing various physiological adaptations. During this time, the balance and relationship between adaptation and recovery is crucial, given the higher training loads/potential injury risk experienced by athletes. It is known that the use of certain recovery modalities (cold water immersion) and nutritional strategies (antioxidants) has reduced training-induced adaptation, particularly related to strength and resistance exercise1. However, the same modalities (cold water immersion) have also shown to improve aerobic-related adaptation2.
This poses another question, as most team sports seldom rely or train one single physiological-based system (for example, the demands of sports such as soccer involve a combination of energy systems utilization), and a “black or white” physiological emphasis approach is limiting and difficult to navigate when prescribing methods to maximize training-induced adaptation. On the other hand, individual-based sports, which can be separated largely between strength/power and endurance, would be more suited to this approach of using “recovery” modalities (or adaptation enhancement modalities) to elicit greater training adaptations. Therefore, during periods of adaptation-related training, some of these modalities or approaches should be avoided.
This trade-off relationship between adaptation and recovery can be difficult to establish/quantify, especially when evaluating potential injury risk for athletes. Fatigue monitoring can help to identify at-risk individuals and to understand and quantify the extent of the stress experienced by the athlete. Athletes will respond differently to varying external loads and stress; therefore, a “one size fits all” approach or solely measuring external load may negate important intelligence relating to how athletes respond and their subsequent fatigue status. Establishing individual “response fingerprints” can enable a surveillance system that provides insights on whether to promote stress/adaptation or recovery in order to maximize the training-performance process.
Another factor to consider is the technical emphasis of the training session. In team sports, coaches often demand high-quality technical/tactical sessions, which they believe to be crucial for subsequent global performance. For example, if this type of session is to be programmed during a period when physiological adaptation is a key component (pre-season or closely following competition early in the season), a decision must be made as to which is the most important factor to promote—i.e., enhance acute recovery to maximize the quality of the technical session or maximize adaptation-related stress for a more physiological gain. A response monitoring framework (discussed later) can help guide some of these decisions, which will be highly individual.
Freelap USA: Cryotherapy is a very complex interaction with athletes, as it may help with local pain but is also known to interfere with the recovery process. When is it fine (if ever) to add cold therapy, and when should we look to other options? What about heat?
Robin Thorpe: First of all, it is important to acknowledge the differences between the various methods of “cryotherapy.” For example, local cooling, cold water immersion (CWI), and whole-body cryotherapy (WBC) are all frequently used in elite sport during acute injury, rehabilitation, and performance recovery settings, which arguably could be displayed on the same continuum of mechanical micro-trauma to structural disruption. Many of these methods are labelled and positioned under the same umbrella of “cryotherapy”; however, the physiological response produced from each of these methods can vary in level and may even vary in physiological response altogether. This largely relates to the states of matter of each method and also the laws of thermodynamics and temperature transfer.
The consensus for “cryotherapy” use in both clinical and performance settings is to first reduce skin temperature, which acts as the first mechanism to reduce peripheral and deep tissue temperature, reduce blood flow, and elicit an analgesic effect3. Cold water immersion will reduce deep tissue temperature at a greater level than local cooling (ice packs) for the aforementioned reasons (law of thermodynamics)3, although local cooling is still widely used ahead of water immersion as the primary method, particularly in clinical/injury/rehabilitation situations. Ultimately, if the aim is to reduce tissue temperature, blood flow, and pain sensation, cold water immersion seems to be the most potent long-standing option compared to local cooling3. Whole-body cryotherapy has often been the preferred method of cryotherapy in recent years, although limited evidence of its efficacy exists4. Recent work has shown that cold water immersion improved measures of recovery to a greater extent than whole-body cryotherapy, and there may even be questions relating to whether or not whole-body cryotherapy reduces tissue temperature altogether.Another question that practitioners should consider is whether cooling is the preferred option for performance recovery, and should it even be in the timeline post injury, says @DrRobinThorpe. Click To Tweet
Another question that practitioners should consider is whether cooling is actually the preferred option for performance recovery, and should it even be in the timeline post injury. Recent work5 has shown the application of heat therapy to be favorable over cooling during the healing process post injury. It seems there is an optimal time to cool and heat during the timeline of injury and performance recovery. Certainly, for performance recovery, monitoring of recovery/fatigue/response can guide the prescription of cooling or heat. In team sport, and particularly soccer, the recovery strategy will alter and vary depending on the training stress induced.
We can subdivide fatigue into:
- Mechanical stress – induced by high eccentric contractions predominantly derived from persistent acceleration/deceleration soccer-specific movements or prolonged high-speed running. Common symptoms including inflammation, edema, soreness, and stiffness.
- Metabolic fatigue – induced by high metabolic cost involving various energy systems. Symptoms include acidosis, glycogen depletion, oxidative stress, and potassium accumulation6.
Understanding these origins can help determine whether or not cooling or heat is the preferred method to improve these systems and processes. Each physiological stress involves a unique recovery timeline to return to homeostasis. This is separated into either a reduction in blood flow (cooling) or an enhancement in blood flow (heat), dependent on the type of physiological stress.
Freelap USA: Monitoring jump training isn’t as easy as it looks in the real world. How do you get athletes to buy into jump testing or any type of test for that matter? Eventually you have to collect some sort of data to track athletes, and that requires participation.
Robin Thorpe: The monitoring of jump protocols has been a popular method to evaluate the force application of athletes for many years, and now with the advancement of technology in sport and the affordability of force platforms, many professional sports teams and practitioners use jump protocols to evaluate the physical status of athletes.
A new “plug and play” era has probably had a negative effect on how the assessments and technology are applied in elite sport at the highest level. It’s not always a simple process to implement assessment protocols into a real-world high-performance setting; however, ensuring the importance of the assessment protocol, timing of the test, and standardization is paramount if the data is to be used to complement the performance and coaching process. In recent years, it seems that this part of the process has been neglected, and the importance has moved toward the actual technological tool itself or the visualization of the data. Arguably, the most important factor (assessment protocol) is overlooked, which may be one reason why many performance/fatigue monitoring frameworks have struggled to impact decision-making and the training process.Many performance/fatigue monitoring frameworks have struggled to impact decision-making and the training process because they overlook the assessment protocol—the most important factor. Click To Tweet
Another factor may be that communication to key stakeholders as to the extent and true capabilities of technology and subsequent information has been exaggerated or misinterpreted, subsequently elevating expectations from various stakeholders and ultimately under-delivering on the outcome of the sports science/performance process. In order to minimize some of these issues, there are four areas (Four Pillars of Confidence) that should be considered prior to implementing any assessment or monitoring tool in a high-performance environment: validity, reliability, sensitivity, and usability.
For example, a monitoring tool needs to have acceptable repeatability in order to be used for subsequent sensitivity to load/stress/competition. Furthermore, just because a monitoring tool is repeatable in another sporting environment doesn’t necessarily mean it will be repeatable in all environments. Therefore, test/retest estimates should be established in each setting. Jump monitoring is just one tool that coaches can use as part of a battery of tests. It is important to ensure each monitoring tool provides a clear indication of the system investigated.
From experience, individualized feedback has generally maintained compliance from an athlete standpoint, and informal, quick, verbal feedback has typically shown to be beneficial in elite team sport athletes. Ultimately, coach buy-in leads to athlete and other practitioner compliance; therefore, relationships and establishing how the coach synthesizes information should be an important factor to consider during the first stage of reporting and feedback processes.
Freelap USA: Some coaches like to lift the day after the game, while some want to facilitate recovery. With research supporting multiple options, how does a soccer (team sport) program best get in its weekly lifts?
Robin Thorpe: Coaches can achieve a resistance exercise session and facilitate recovery simultaneously. There is some evidence that increasing testosterone and, in turn, enhancing the testosterone-cortisol ratio may be a favorable endocrinological environment to facilitate general recovery7. Resistance exercise will likely increase testosterone, so amalgamating the two processes without further reducing recovery may be an efficient option as part of the performance and training cycle. Furthermore, the active nature of resistance exercise will increase global blood flow, which may be favorable for metabolic clearance and subsequent general recovery.
In soccer, it is the tissues and systems of the lower limbs that may experience mechanical damage, metabolic, and/or neuromuscular fatigue. Therefore, resistance exercise of the upper limbs (still an important physical performance attribute) would be a suitable option to potentially improve both endocrinological processes and performance strength adaptation together. The use of resistance exercise during a recovery-themed day can be advantageous, as it creates a cultural emphasis of active-based modalities rather than passive. It seems passive recovery modalities such as massage, manual therapy, and sequential pneumatic compression are becoming more and more popular with athletes and some practitioners, even considering the general and often lack of evidence supporting benefits to enhancing recovery. An active practitioner-guided, self-managing athlete inside and outside the training facility may be a more favorable concept and culture for high-performance environments and teams.The use of resistance exercise during a recovery-themed day can be advantageous, as it creates a cultural emphasis of active-based modalities rather than passive, says @DrRobinThorpe. Click To Tweet
The day following the game is also normally a lower load day, so resistance exercise load would not compound any other on-field/conditioning load already programmed. When technical/tactical sessions induce high load, resistance load must be carefully adjusted to manage the overall global stress of the athlete. It’s important to ensure that load is quantified during both on-field technical/tactical and resistance sessions.
Session ratings of perceived exertion (S-RPE) have been shown to provide a standard measure to use interchangeably. However, during intensive periods of competition, general/mental/neuromuscular fatigue may be high and, therefore, adding extra nervous system resistance exercise may not be suitable. Monitoring response/fatigue status and the various elements of recovery and physiological systems is a recommended approach to quantify the extent of fatigue and ensure that this resistance exercise is applied during suitable timepoints and avoided at others.
Freelap USA: Load management is often about reducing total stress or manipulating eccentric demands, but what about biochemical strain? A lot of coaches deal with athletes who are burned out on training because they are going hard on a bike or even a pool session. How do we manage the training load psychologically?
Robin Thorpe: First of all, “load management” isn’t solely about reducing stress or “putting on the brakes.” “Load management” also includes increasing the load or stress depending on the situation or the athlete’s current physical/fatigue status. As previously stated, the athlete’s “response” to load will vary largely and during different periods; therefore, this ought to be assessed and monitored.
A balance between match/training load and recovery is paramount in order to optimize training responses and adaptation in athletes. Overtraining and/or fatigue accumulation can be the result of an increased training load, whereas detraining may be the result of a reduction in training load. Given the importance of recovery within the training process, attention in the literature has increasingly centered upon developing noninvasive monitoring tools that serve as valid and reliable indicators of the response/fatigue status in athletes.A balance between match/training load and recovery is paramount in order to optimize training responses and adaptation in athletes, says @DrRobinThorpe. Click To Tweet
In order to serve as a valid indicator of fatigue/response in elite sport, prospective tools should be simple, quick, inexpensive, and easy to administer. Furthermore, potential measures should be sensitive to training load, and their response to acute exercise should be distinguishable from chronic changes in adaptation. In team sports such as soccer, any fatigue/response assessment must be non-exhaustive and quick and easy to administer to ensure frequent application over the long and congested competitive period.
Recent investigations with elite soccer players have shown that perceived ratings of wellness and ANS-derived heart rate (HR) measures were sensitive to both daily and within-weekly changes in training load8. Perceived ratings of wellness, HR-response indices, and potentially structural extensibility assessments may be useful as a fatigue/response monitoring framework in elite athletes. Practically, the initial use of perceived ratings of wellness can also create avenues for the further assessment of these physiological/anatomical systems.
For instance, elevated perceived muscle soreness may prompt further investigations into strength and/or extensibility-focused structural assessments. Such approaches may be used in order to explore potential anatomical disruption. Moreover, these assessments may also lead to further evaluation of the autonomic nervous system via HR-response quantification. For example, during periods of fixture congestion, players may suffer from potential debilitating symptoms associated with overreaching. Further investigation via the use of heart rate indices may provide greater insight into the responsiveness of the autonomic nervous system. This information can then be used to better guide training load/recovery intervention prescription for these individuals.
Monitoring the external load of athletes is a more common approach to athlete status evaluation and is certainly beneficial in order to understand the varying load elements. However, each athlete, and at varying timepoints the same athletes, is likely to respond differently. Monitoring “response to load” or fatigue provides information to coaches and practitioners to prescribe and modify training to provide an “optimal load” on an individual basis.
Cycle and pool sessions are popular training methods on recovery days due to their lower mechanical load and the variance from normal training environments. However, like any other training modality, the manipulation of intensity/time can provide higher physiological demands. Typically, in team sports training load is monitored by ratings of perceived exertion (RPE), heart rate, and global positioning systems (GPS), and this should not stop on recovery days, resource permitting.
RPE is a valid tool to track the physical and mental impact a recovery session (pool or bike) may have on the athletes. Furthermore, during times of increased competition or psychological demand, it is important to consider the mental fatigue of the athletes. This can also be exacerbated during periods of high-pressured competition and technical/tactical overload.
Simple perceived ratings of wellness questionnaires have shown to be valid and sensitive in elite individual and team sport athletes. Therefore, utilizing this method and including a questionnaire relating to mental fatigue may be a suitable starting point to track this key factor. However, validation and sensitivity research are yet to be completed within this particular area. Other methods, like heart rate variability, may also provide some beneficial insights into mental/cognitive fatigue via the autonomic nervous system, but more work is required on this topic.
The ALTIS/Brains Bioceutical Living Lab brings together interdisciplinary experts to co-create, explore, experiment, and evaluate—in real-world environments—new ideas within the natural training and competition environment of elite athletes.
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8. Thorpe, R.T., Atkinson, G., Drust, B., and Gregson, W. “Monitoring Fatigue Status in Elite Team-Sport Athletes: Implications for Practice.” International Journal of Sports Physiology and Performance. 2017; 12(Suppl 2):S227–S234. doi: 10.1123/ijspp.2016-0434. Epub 2017 Jan 17.