Relaxation and Recovery in Sport and Performance
Summary and Keywords
The sport and performance environment is highly demanding for its actors. Therefore, recovery from work and sports requires special attention. Without adequate recovery, optimal performance is not attainable. It depends, however, on the individual what adequate recovery actually is. An extremely demanding event for someone may not be as demanding for someone else. Every individual perceives his or her environment differently and therefore has to choose his or her response or prevention strategy accordingly. Monitoring one’s recovery-stress states might be a promising starting point to establish individual baselines and further regulate training or work intensities. Relaxation in terms of implementing systematic relaxation techniques seems to be an adequate approach. These techniques can be divided into muscle-to-mind and mind-to-muscle techniques focusing either on the training of one’s sensitivity to muscle tension or on the cognitive processes involved in relaxation. Whether the recovery process is finally successful depends on if the chosen methods fit the purpose of recovery (i.e., response to cognitive or physical demands), the setting/circumstance (i.e., time and place), and how comfortable one feels with the specific recovery strategy.
Recovery is a crucial part of any performance system. To be able to produce optimal performances, individuals have to (be prepared to) respond to bio-psycho-social demands adequately as these demands affect a person’s health status. Sustained “inability” to cope with these demands could lead to critical disadvantages quickly. Therefore, recovery either as a response to demands or as a continuous state is needed to actually maintain performance. Within this construct, systematic relaxation is a fundamental way to initiate recovery and to support this process (Brown & Fletcher, 2017; Pelka et al., 2016, 2017). This article will discuss recovery and relaxation in sports and in the work context as important platforms for performance, while taking health-related issues into account.
The basic idea of recovery is that resources need to be restored and a homeostatic and biorhythmic balance regained. Kallus and Kellmann (2000) described the recovery process as an inter- and intra-individual multilevel process for the reestablishment of performance abilities, which includes an action-oriented component and self-initiated activities that can be systematically used to optimize situational conditions to build and restore personal resources and buffers. Based on this definition, recovery ends when a psychophysical state of restored efficiency and homeostatic balance is achieved. This multilevel process is highly individual and has several dimensions, that is, physiological, mood-related, cognitive, behavioral, social, and emotional recovery (Kallus & Kellmann, 2000). Essentially, recovery depends on a reduction of, a change of, or a break from stress and is a gradual and cumulative process that is dependent on previous activities (Kellmann, 2002). In addition, recovery is tightly linked to environmental circumstances; for example, if one is disturbed in his/her preparation or sleeping habits, it influences the entire process. Furthermore, recovery can affect the sympathetic parasympathetic balance (Bastos et al., 2012).
In practice, recovery can be divided into active, passive, and pro-active methods (Kellmann, 2002). Active recovery involves moderate exercise during the recovery process to eliminate the results of fatigue through a target-oriented physical activity (e.g., low-intensity cycling for a certain amount of time on an ergometer after a Tour de France stage or a short walk between meetings in a business setting). A passive approach could consist of hot and cold baths, massages, sauna, or sitting and lying quietly. Physiological reactions to physiological stimuli such as heat, cold, or pressure activate psychological and biological processes to restore pre-task/performance states are initiated. Whenever recovery includes a purposeful, self-initiated, and self-determined action, it is considered pro-active recovery (e.g., stretching to overcome the time span of a medal ceremony when there is competition on the following day or taking a post lunch nap previous to late scheduled meetings). One’s perception of recovery is important as well; if it is positive, crucial changes in outcomes are likely (Botterill & Wilson, 2002). Recent research in football (Fullagar et al., 2016), rowing (Kölling et al., 2016), weightlifting (Schimpchen et al., 2016), strength training (Raeder et al., 2016), and cycling (Hammes et al., 2016) show the high value of the recovery process.
Optimal performance is only achievable if performers are recovered appropriately after exposition to demanding activities, and optimally balance stress with adequate recovery (Kellmann, 2010). In many tasks in contemporary society, people are confronted with an enormous work load and an increasing amount of competition. Individuals have to invest a large amount of time and intense effort to stay on top in their area of expertise. Every field has its own demands and specialties to which one has to respond. In order to deal effectively with such demands, individuals need to rely on their resources. Introduced into recovery-and-stress research three decades ago, resources can be divided into consumptive and permanent resources (Kallus, 2016). Acutely demanding issues affect consumptive resources in the first instance as the response to those demands mobilizes and utilizes resources to allow an active coping. Chronically occurring demands are more prone to have negative effects on permanent resources. Additionally, permanent resources could be at stake in acute stress situations.
Kellmann (2002) described the interplay between stress states and recovery demands of an individual, based on the assumption that an individual has limited resources to compensate for and cope with stressors (Hampel & Petermann, 2006). Under increased stress and the inability to meet increased recovery demands (i.e., limited quality of necessary recovery activities to level-out the current recovery-stress state), individuals experience even more stress. At this point, they may be stressed to the point that they fail to find or invest time to adequately recover, or to consider better ways of coping with their situations. Failing to adapt has the potential to lead to even more stress, resulting in the need for more recovery time. This situation can be handled until the recovery demands surpass the resource limit or the stress states exceed the stress capacity. Beyond these points, a performer cannot meet recovery demands without additional recovery activities. Stress will accumulate, and without intervention, severe consequences are more likely to occur.
In both cases—recovery either as a response to demands or as a continuous state that is needed to actually be able to perform—recovery is closely connected to the tasks or the demands one is exposed to. Therefore, performance characteristics are of high value and great interest when examining recovery-stress states.
Recovery and Performance
Performance in its simplest and broadest form is the action or behavior itself, relevant to respective goals and is measured in terms of each individual’s proficiency. In nearly all tasks, performance, similar to recovery, is multidimensional: that is, it requires a consideration of many different combinations of human attributes. Individuals call on many attributes to perform their jobs, and each of these attributes is associated with unique aspects of performance (Landy & Conte, 2007). These aspects differ in every job domain; however to provide a detailed overview, sports perspectives will be discussed in detail in terms of how performance is affected by recovery in this domain. Besides direct influences of recovery-stress states on performance, another aspect that needs to be considered is overall health. An imbalanced recovery-stress state can be closely linked to various health issues that may affect performance across time.
Characteristics of Recovery and Performance
The intense mental and physical demands placed on elite athletes are important aspects of a sporting career. Impacted by a variety of bio-psycho-social factors, optimal performance in sports and increased overall well-being is only achievable if demands are paired with appropriate and adequate recovery. In addition to well-reported physical and competition demands, athletes face a unique array of workplace stressors. Those include the pressure of increased public scrutiny through mainstream and social media, limited support networks due to relocation, group dynamics in team sports, and the potential for injuries to end careers prematurely. Organizational demands are an unavoidable aspect of participation in contemporary sport (Fletcher, Hanton, Mellalieu, & Neil, 2012). Therefore, as demands are multifactorial (Nédélec et al., 2013), recovery needs to be multi- and interdisciplinary indeed. Additionally, physical and mental fatigue seem to be interdependent as well (Marcora, Statiano, & Manning, 2009; Sutherland, Alexander, & Hutchison, 2006). For recovery to be holistic, physical and psychological parameters need to be considered. For example, physical recovery (Hausswirth & Mujika, 2013) following dehydration, glycogen depletion, muscle damage (Nédélec et al., 2012) or psychological recovery following mental fatigue (Nédélec et al., 2013) needs to be addressed. Moreover, competitive anxiety should be addressed (e.g., Fletcher & Hanton, 2001; Neil, Mellalieu, & Hanton, 2006) as well as competitive demands and, recently, more thoroughly investigated organizational demands (e.g., Fletcher et al., 2012). Explicit variables that play crucial roles are, for example, factors intrinsic to the sport (e.g., regarding training and competition), roles in the sport organization (e.g., role conflicts and ambiguity), sport relationships and interpersonal demands (e.g., personality type), athletic career and performance development issues (e.g., income and funding, career goals, position insecurity), organizational structure, and climate of the sport (e.g., cultural and political environment, coaching style, inadequate communication channels; Fletcher et al., 2012). All those factors are contributors to optimal performance and well-being and need to be balanced adequately.
Similarly, this complex construct applies to the regular work environment (Coffeng, Hendriksen et al., 2014), including the sport environment. Coffeng, Hendriksen, and colleagues (2014) report that by taking the socioecological approach by McLaren and Hawe (2005) into account, working environments consist of multiple social, physical, and environmental conditions, which jointly influence physical and mental well-being. With increasing workloads during the past decades, the number of employees experiencing psychological problems related to occupational stress has increased rapidly in Western countries. At both the societal and individual level, costs are considerably high (van der Klink, Blonk, Schene, & van Dijk, 2001). Absenteeism, presenteeism, loss of productivity, or increased health care consumptions are societal issues; and mental fatigue, depressed mood, anger, anxiety, and sleep disturbances are individual issues. Those issues are often classified as neurasthenia, adjustment disorders, or burnout (van der Klink et al., 2001). Based on those consequences, the importance of recovery processes for prevention of health issues has been identified in several studies. Both the World Health Organisation and the European Union recommend the implementation of health promotion programs to positively affect absenteeism and presenteeism (Conn, Hafdahl, Cooper, Brown, & Lusk, 2009; WHO, 2010). Insufficient recovery is related to various health parameters, such as the risk of cardiovascular diseases (van Amelsvoort, Kant, Bültmann, & Swaen, 2003), general health (Sluiter, Frings-Dresen, van der Beek, & Meijman, 2001), well-being (Fritz, Sonnentag, Spector, & McInroe, 2010), injuries (Brink et al., 2010; Swaen, van Amelsvoort, Bültmann, & Kant, 2003) or low back pain (Mierswa & Kellmann, 2015). Consistent with these results, persons with a high need for recovery were at twice the risk of sickness absence in the following two years, compared to people with a high recovery status (de Croon, Sluiter, & Frings-Dresen, 2003). Need for recovery seems to be an early indicator for mentally and physically fatigue induced through work and reflects the need to relax after it (Coffeng, Boot et al., 2014) Consequently, recovery is necessary to prevent accumulation of stress over time, as it is linked to the development of health complaints.
In the same vein, Raysmith and Drew (2016) revealed that performance success or failure is influenced by an athlete’s health status during preparation for competition. Training loss of around 20% due to injury or illness decreased the likelihood of achieving a performance goal by seven times. Therefore, an athlete’s health status and its influence on training availability is a major determinant of an athlete’s chance of performance goal success or failure (Raysmith & Drew, 2016). This view is also shared by Meeusen et al. (2013) who stated that successful training most likely involves overload but also avoids the combination of excessive overload and inadequate recovery. Therefore, it is essential to implement appropriate regeneration phases in training regimens that aim for well-being and competitive success. Optimal recovery is a consciously planned activity that matches situational and environmental needs of an athlete in rest, and results in regaining an optimal performance state. An appropriate example of a competition setting is multi-stage cycling, as a healthy recovery-stress balance is crucial in these competitions when athletes are exposed to highly stressful circumstances over an extended period of time (Filho et al., 2013). Filho and colleagues (2015) suggest that the recovery-stress balance should be monitored closely to be able to respond to demanding events immediately and ensure the possibility for the athletes to obtain peak performances.
Research has established relationships between training intensity, frequency, and duration and their consequences for performance and health. For example, it was shown that inadequate recovery between matches because of a congested match calendar can lead to fatigue and increase the risk of injury associated with overuse and poor performance during subsequent performance (Dupont et al., 2010; Laux, Krumm, Diers, & Flor, 2015). The importance of regaining an adequate working state for consistently successful performance is widely recognized by athletes and their coaches, and overtraining syndrome and burnout syndrome remains among the most relevant problems encountered in competitive sports (Meeusen et al., 2013).
Consequences of Recovery-Stress Imbalances
Designing adequate training regimens is a sophisticated task. The complexity of fine-tuning them can be recognized when considering all factors that influence performance, both inside and outside of the specific domain, such as training (e.g., extent, intensity, training techniques, periodization), lifestyle (e.g., sleep, nutrition, recreational activities), state of health (e.g., cold, infections), or environment (e.g., family, team members, school/university; Kellmann, 2002). All of these factors need to be considered when targeting optimal and appropriate performance as all are potential demands on performers.
When people are not aware of the importance of their recovery-stress balance and its actual state, decisive disadvantages can arise quickly. Inappropriate time management, disproportionate and excessive training/workload, or incorrectly set priorities are frequent incidents, which could potentially lead to those disadvantages. The most prominent consequences of imbalances in recovery versus stress in sports are underrecovery, the overtraining syndrome, and the burnout syndrome. These patterns differ in intensity, severity, and longevity. The relationship between these three states could be conceptualized with underrecovery as the antecedent of overtraining and burnout in terms of individual well-being, performance decrements, and influence on short- and long-term development (Kellmann, 2002).
If recovery time is too short or disturbed by any circumstances, underrecovery may occur. Underrecovery is defined as the imbalance of recovery periods and the daily life demands on a person. These demands can be intensive practice, competitions, as well as other stressors linked to the performance and everyday life of an athlete. For example, absence from family because of extensive travel can be an important stressor disturbing adequate recovery before and after games. Other potential risk factors include monotonous training programs, training sessions that are too long, and ignoring training principles or periodization (not including rest days or periods of lower intensity; Kenttä & Hassmén, 2002). While short periods of underrecovery can be compensated by the athletes’ use of recovery strategies (e.g., systematic relaxation techniques), chronic underrecovery can have both short-term and long-term consequences. Short-term consequences include increased feelings of tiredness, exhaustion, and lethargy, decreased motivation, as well as development of negative cognitions toward upcoming activities, all of which negatively influence future performance (Kellmann & Altfeld, 2014a). Unpredictable events and changing conditions are also likely to occur in daily routines. These can vary and might include variability in the environmental conditions (e.g., noise, heat, problems with facilities), self-related issues such as tension, disturbing cognitions or inner conflicts, or even domestic issues (e.g., family problems, extra workload), which could have a deep impact on recovery. This phenomenon is termed disturbed recovery (Kellmann, 2002) and is present when conditions for optimal recovery are present, but the process is interrupted by environmental issues (Kellmann, Altenburg, Lormes, & Steinacker, 2001). During these moments of deep concentration and attempted relaxation, any disturbance could be experienced as a stressor and lead to underrecovery.
If an athlete reaches the state of chronic underrecovery, small periods of rest or spontaneous interventions are often ineffective, requiring longer rest periods (from several weeks to months) and professional help from medical doctors or psychologists. With additional training load, recovery demands increase proportionally. A short-term planned sacrifice of recovery (e.g., a day off following a practice session that was more strenuous than expected while planning the training regimen), however, enhances long-term effects. If training load and intensity increase over a longer time with inadequate or inappropriate recovery, the individual experiences long-term underrecovery that may result in overtraining. At each stage of Kellmann’s model, recovery can work as a regulation mechanism; the higher a person’s stress state, the higher the demand for recovery to reach individual optimal recovery-stress states. It has to be stated, however, that being high on stress does not necessarily imply negative consequences as long as recovery demands are met accordingly. Thus, if athletes lack the necessary coping strategies, stress can become chronic with overtraining as an inevitable consequence (Gustafsson, Kenttä, Hassmén, & Johansson, 2008). Overtraining can be viewed as the result of too much training and stress with insufficient recovery (Meeusen et al., 2013). Therefore, underrecovery syndrome (insufficient and/or lack of recovery time) can be characterized as a longer-lasting pre-condition to overtraining syndrome. Overtraining develops over time and occurs when athletes are unable to refill their energy stores adequately and continue to practice in a tired state (Kellmann & Altfeld, 2014b). Research has revealed that the most frequent causes of overtraining are (1) too much stress and pressure, (2) too much practice and physical training, (3) boredom because of too much repetition, and (4) poor rest and lack of proper sleep. Overtraining can have both short- and long-term effects. Besides the short-term consequences of tiredness and exhaustion, the long-term consequences include psychological, physiological, and/or hormonal changes that could a) be directly related to performance, in terms of decreased or stagnating performance; and b) indirectly through other symptoms. Physiological changes include chronic muscle or joint pain, and elevated resting heart rate (Small, 2002). In addition, personality or mood changes may occur. Increased impressions of fatigue could arise frequently as well as a general lack of enthusiasm or ambition (Lazarus, 2000). Often, individuals can cope with these situations, but when a heavy training load is added to already high stress, athletes’ resources may be depleted quickly, as highlighted by research indicating that injuries, illness, or infections appear more frequently during these times than during optimal recovery-stress states (Gustafsson, Kenttä, & Hassmén, 2011; Laux et al., 2015).
Overtraining has been primarily associated with physiological stress and is a particular characteristic of sports. On the contrary, the burnout syndrome considers psychological factors to a greater extent (Gustafsson et al., 2011) and is prevalent in various performance areas and disciplines (Leiter, Bakker, & Maslach, 2014; Maslach, Schaufeli, & Leiter, 2001). After Maslach and Jackson (1984) intensified research on burnout in organizational settings, the burnout syndrome has been acknowledged as a prolonged response to chronic emotional and interpersonal stressors on the job that is defined by the three dimensions of exhaustion, cynicism, and inefficacy (Maslach et al., 2001).
A sports-related integrated framework was developed by Gustafsson et al. (2011) for the purpose of directing future research in sports domain. They proposed that burnout consists of major antecedents, early signs, entrapment, personality, coping and environment, and key dimensions and consequences, including fully developed burnout and in many cases withdrawal and exit from sport (Gustafsson et al., 2008). Burnout denotes a negative emotional reaction to sports participation, and while it is known that overtrained athletes can still maintain their performance motivation to keep training, a burned-out athlete will commonly have no motivation to pursue his/her activity (Fry, Morton, & Keast, 1991). Similarly, burnout has been defined as an exhaustive psychophysiological response to massive chronic stress that develops gradually (Gustafsson, Kenttä, Hassmén, Lundqvist, & Durand-Bush, 2007). Burnout has also been shown to lead to affective, cognitive, motivational, and behavioral consequences with chronic emotional and physical exhaustion as key components (Goodger, Gorely, Lavallee, & Harwood, 2007).
In sports, the symptoms of burnout resemble those of the overtraining syndrome and can be linked to three indicators suggested by Raedeke (1997): (1) physical and emotional exhaustion, (2) reduced sense of personal accomplishment, and (3) sport devaluation. In the end, it often requires a long break from organized sport-related activities to recover from chronic stress. Repeated episodes of overtraining appear to increase the risk of burnout, with the motivation to continue training being the essential factor to clarify the seriousness of the overtraining syndrome (Raglin, Sawamura, Alexiou, Hassmén, & Kenttä, 2000).
A way to acknowledge individual responses to environmental and training and competition demands would be monitoring recovery-stress states. The regular use of appropriate tools is an important prerequisite for monitoring the training or workload and well-being of athletes and workers (Halson, 2014). There are a number of instruments that assess the recovery-stress state from different angles and aim for an early detection of imbalances (Brink, Visscher, Coutts, & Lemmink, 2012; Meeusen et al., 2013). Objective diagnostic methods seek to assess physiological, biochemical, or performance parameters whereas subjective methods focus on psychological variables (Saw, Main, & Gastin, 2016). Subjective diagnostic instruments are time saving, cost effective, and easy to integrate into work and training schedules. Considering the variability in the response to training and workload in individuals underlines the importance of the assessment of subjective well-being (Meeusen et al., 2013). For a comprehensive review on the use of subjective diagnostic instruments, see Saw et al. (2016). Established questionnaires in applied practice settings with published manuals are the Recovery-Stress Questionnaire for Athletes (Kellmann & Kallus, 2016) and the Recovery-Stress Questionnaire for Work (Jiménez, Dunkl, & Kallus, 2016), the Profile of Mood States (McNair, Lorr, & Droppleman, 1981), the Daily Analyses of Life Demands for Athletes (Rushall, 1987), or Rating of Perceived Exertion (Borg, 1998). Other recently published options in sport are the recently developed Acute Recovery and Stress Scale (Kellmann, Kölling, & Hitzschke, 2016; Nässi, Ferrauti, Meyer, Pfeiffer, & Kellmann, 2017) and the Short Recovery Stress Scale (Kellmann et al., 2016), two instruments developed to measure the acute recovery-stress state of athletes. These questionnaires assess respective states using different time frames, ranging from “right now” to “seven days.” Using these monitoring instruments in accordance with appropriate evaluation by sports/work psychologists or sport scientists can assist in regulating stress and recovery in terms of individually tailored recovery responses to stress demands.
Being able to react to or prevent the potential consequences of imbalances (see “Recovery and Performance” in this article) requires an appreciation of the interconnectivity of factors contributing to the performance system. While there is a range of recovery strategies, individuals will respond to them differently, and athletes need to find a set of appropriate strategies that suits their unique needs. This implies conscientious selection and consistent training of those strategies.
Having appropriate recovery strategies is a crucial part of a successful recovery process, and includes a variety of ways to achieve that state of well-being (Kaur, Agarwal, & Babbar, 2014; Kudlackova, Eccles, & Dieffenbach, 2013; Pelka et al., 2016). People sleep, nap, or meditate to calm down from the various stressors they were exposed to. Even running, dancing, or other strenuous exercises could be declared relaxing if they are appraised as relaxation. Except for the latter examples, all those recovery strategies have been examined and obtain scientific background, experimental support, and validation. There are standardized methods applied and validated in clinical settings, and further tested in sport and work contexts. The application of these methods in clinical settings has brought along a more exact and differentiated understanding of relaxation, for example, the subjective impression of feeling well after a nap has been updated and is supported by vegetative and electroencephalographic feedback (Lovato & Lack, 2010).
A specific type of recovery strategy is systematic relaxation techniques. To utilize effectively these techniques need to be taught and practiced. Petermann and Vaitl (2014) report hypnosis, autogenic training, meditational (Eastern) techniques, imagery, progressive muscle relaxation (PMR), and biofeedback as being the standard repertoire of relaxation strategies. Kudlackova and colleagues (2013) found that autogenic training, Eastern relaxation, and progressive muscle relaxation were the less-used techniques compared to deep breathing, meditation, and imagery in a study investigating the use of relaxation techniques in professional and semi-professional sports. Additionally, two emergent approaches are neurofeedback (Mirifar, Beckmann, & Ehrlenspiel, 2017) and mindfulness (Gross et al., 2015). Previous research has divided these techniques into two separate groups (Davidson & Schwartz, 1976; Kenttä & Hassmén, 1998; Pelka et al., 2016). Muscle-to-mind techniques focus on the training of one’s sensitivity to muscle tension (e.g., PMR, breathing techniques) while mind-to-muscle techniques focus on the cognitive processes involved in relaxation (e.g., autogenic training, hypnosis). Although all these techniques share basic integral parts, each method has a different impact on an individual. Shared parts are, for example, self-control, concentration training, calming down, and an improvement of well-being; all are involved in providing optimal internal conditions. Regarding the general psychophysiological relaxation response, neuro-muscular, cardiovascular, respiratory, electro-dermal, and central nervous system related changes based on the relaxation response have been examined. More specifically, vasodilation, a decrease in heart rate, an increase in heart rate variability, a decrease in breathing frequency, a decrease in muscle tone, a decrease in skin conductance level, and a decrease in oxygen consumption are signs of an enhanced relaxation response (e.g., Dolbier & Rush, 2012; Jerath, Crawford, Barnes, & Harden, 2015; Lewis, Williams, & Olds, 2007).
Davidson and Schwartz’s matching hypothesis (1976), Kudlackova et al.’s study (2013), and Lehrer (1996) suggest that muscularly oriented methods have the greatest effects on the musculoskeletal system and autonomically oriented methods on the autonomic nervous system. Strategies with predominant cognitive components were associated with decreases in amount of worrying, self-assessment of anxiety or pain, and an increase in the ability to concentrate (Jain et al., 2007). The most prominent techniques are autogenic training and hypnosis. On one hand, autogenic training is a self-hypnotic method that uses trance-inducing procedures similar to hypnosis (Luthe & Schultz, 2001). Self-suggestions of heaviness and warmth in the limbs, a calm and regular heartbeat, coolness in the forehead, warmth in the solar plexus, and automatic breathing are excerpts of the practices used in autogenic training. Hypnosis, on the other hand, is defined as an altered state of consciousness that can be induced by a procedure in which a person is in an unusually relaxed state and responds to suggestions for making alterations in perceptions, feelings, thoughts, or actions (Barker & Jones, 2008).
Strategies with predominant skeletal muscle components tend to produce greater muscular effects, that is, a decrease in heart rate and blood pressure and an increase in finger pulse volume. Different versions of PMR, biofeedback, yoga, and systematic breathing are the most investigated techniques in this domain (Pelka et al., 2016). PMR and its derivations have received the most attention in a scientific context. Following the theoretical foundation of Jacobson (1938), the central aim of a relaxation method is the deliberate and continuous reduction of tension in specific muscle groups of the locomotor system. The original method, in which the emphasis is laid on training of self-perception of muscular sensations, has greater effects on somatic issues while the revised version, in which producing a subjective experience of relaxation is the key strategy, has a greater impact on cognitive symptoms (fears and anxieties; Dolbier & Rush, 2012).
A review in Behavioral Medicine Research on the use of PMR in clinical trials revealed moderate to large effect sizes on the effectiveness of PMR (Crawford et al., 2013). Biofeedback addresses oscillation by stimulating and exercising modulatory reflexes in the central nervous system leading to increases in baroreflex gain, modulation of blood pressure, and a decrease in anxiety and depression (Lehrer, 2012). Yoga is a mind-body intervention that among other benefits can be effective in the treating anxiety. It activates the parasympathetic branch of the nervous system, replacing sympathetic nervous system overdrive, or the flight-or-fight response, with the relaxation response and balancing the nervous system. Yoga therapy increases positive coping skills and builds self-esteem without harmful side effects (Williams-Orlando, 2013). Systematic breathing is reported as being one of the simplest and most effective ways to control anxiety and muscle tension (Pelka et al., 2016). Williams and Harris (1998) state that breathing in and holding ones breathe increases muscle tension whereas breathing out decreases muscle tension. A slow and deliberate inhalation-exhalation sequence will help one to maintain composure and control over tension levels during stressful events (Weinberg & Gould, 2010).
According to the overall recovery concept, research reports different goals of relaxation strategies for different application times (Baumann, 2006; Kellmann, 2002). The recovery response is different for short-term relaxation prior to competition, relaxation between training sessions or other periods of stress, and after training and/or competition. It has been postulated that each intervention time has a different impact on the participant, with the pre-stress approach aiming for concentration improvement, self-reflection, and mental rehearsal of the competition; the in-between approach aiming for the conservation of mental energy and toughness; and the post-stress approach aiming for the restoration of mental balance and a sophisticated preparation for upcoming events. While the majority of research on relaxation strategies has focused on coping with anxiety and arousal regulation (e.g., Hanton, Wadey, & Mellalieu, 2008), a secondary beneficial function of relaxation, the promotion of recovery (Birrer & Morgan, 2010), has more recently been proposed by Kellmann (2002). Although a number of studies have demonstrated the positive effects of relaxation, including a shortening of healing time or the reduction of stress (Broadbent et al., 2012), a positive influence on the cardiac parasympathetic tone (Sakakibara, Takeuchi, & Hayano, 1994), a positive impact on recovery time following sport injury (Schwab Reese, Pittsinger, & Yang, 2012), and improved performance in repeated sprint performance (Pelka et al., 2016), more scientifically sophisticated and robust studies are warranted.
Based on the characteristics of sport and performance, when addressing recovery one must consider the individual variability of the stress response. Whether the recovery process is successful depends on if the chosen methods fit the purpose of recovery (i.e., a response to a cognitive load or a physical load) and the setting/circumstance (i.e., time and place; immediately between two tasks, within a few hours, or within a few days; Howatson, Leeder, & van Someren, 2016). This process is further mediated by how comfortable one feels with the specific recovery strategy. The individual that aims for optimal performance and a balanced recovery-stress state must be aware of all the factors that can impact the recovery process. These include training (e.g., Meeusen et al., 2013), general health (e.g., Raysmith & Drew, 2016), personality factors (e.g., Tranaeus, Johnson, Engström, Skillgate, & Werner, 2014), the capability of applying appropriate recovery strategies (e.g., Pelka et al., 2017), and lifestyle (e.g., Marioni, van den Hout, Valenzuela, Brayne, & Matthews, 2012).
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