Training Theory and the 4 Levels of Sport

By Russ Ebbets

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Several years ago I was asked to give a clinic in New Jersey. I was to talk on injury prevention and crafted the presentation around two things – that injury prevention in track & field should be an ever-present concern for a coach and secondly, that a comprehensive injury prevention program could be formulated with forethought and minimal expenses.

In my opening remarks, I mentioned the name Tudor Bompa and the first hand shot up. First question of the day.

Who is Tudor Bompa?

I was surprised by the question but took a 20-second detour to introduce one of the world’s leading training theorists of the last 50 years. I asked the audience – how many are familiar with Bompa’s work? Figured I would establish a BIG common denominator within this audience and draw on it throughout the presentation.

Three hands went up, three. There were between 80-100 coaches in the room. For a long second, I considered some options. The whole presentation hinged on contributions Bompa and several other iconic training theorists had made. My miscalculation necessitated a mid-course correction, from the start. The focus was shifted from nuanced insight to basic fundamentals. In the end it all worked out, fundamentals are always valuable.

To that end this piece will discuss eight training theory fundamentals and then apply them via the four levels of sport. Hopefully this will illustrate a wide range of concepts and clearly demonstrate how some concepts are of greater or lesser import depending on the particular level of sport one is applying them to.

A Primer in Training Theory

Periodization Defined

Sport scientist Richard Bucciarelli has defined periodization as “the systematic planning of athletic and physical training. The aim is to reach the best possible performance in the most important competition of the year.” (2016)

There are three important components to Bucciarlli’s statement. Firstly, there needs to be a “systematic plan” implying there are steps or procedures that happen or evolve in an orderly, versus random, manner.

Secondly, the time, effort and energy that goes into this plan is directed towards a competitive effort, “the best possible performance.” Periodization is used to realize human potential and to push the limits of speed, strength and endurance into uncharted territories. Periodization is not for simple fitness, weight management, stress release, lifelong fitness or children. Periodization is to enhance the competitive performance of adults.

The final component is that performance takes place “at the most important competition of the year.” Periodization is not to prepare the body’s physiology and musculature to a fine point to produce a superlative effort the next time one is having a “good day.” But rather periodization is the masterful and artful preparation by the coach to have the athlete physically, technically, tactically and psychologically firing on all cylinders, so the athlete is able to accomplish pre-determined goals as a season/career training plan dictate. Culmination of this plan is usually a season ending “terminal competition.” These “pre-determined goals” may take months to years to realize.

The career of an athlete is short. The masterful and artistic application of periodization allows for the coach and athlete to maximize skills and abilities when needed.

If it is true, that most of humanity’s forward thinking is only 30 seconds into the future (about as far as one can see) one can begin to understand the novelty and challenge periodization presents for many people.

Time, Time, Time

Periodization is time management in an athletic sense. A season is really a collection of smaller time units broken into weekly, monthly or seasonal chunks of time. While this may be self-evident for a coach who uses the various methods to manage time (i.e. journals, calendars, cell phone planners, etc.) this may also represent a “great unknown” to the person whose hours are spent rebounding from one text message to the next with lives spent one day at a time.

The concept of time management and forethought is a core principle of sport scientists of the past. Bompa in a Track
Coach interview stated, “Planning to me is the key to everything,” (TC#164). Bompa also stated that “time is quite often the limiting factor in training,” (Bompa, 1983). Even accomplished athletes have noted the critical importance time plays in their development. The great miler, Jim Beatty stated, “One habit that anyone involved in sport cultivates is time management.” (TC #166).

An athlete’s career has a limited time span. Performance at the highest levels can roughly run from ages 18-30 before the erosion of skills and the distraction of responsibilities begins to detract from the quality and quantity of time, effort and energy that produces an evolving, superlative result.

To that end it becomes imperative the coach, athlete or parent create a training environment that capitalizes on the time at hand. This allows for the planning and forethought that goes into the various training cycles. Meshing these cycles together, in a sequential manner, enhances the work of training.

The Evolution of Thought

Physical training is about the management of physical stress. The concept of stress evolved throughout the professional career of endocrinologist Hans Selye. In his classic book The Stress of Life, Selye details his 20-year journey to validate his belief that at the core of all human maladies is an inappropriate response to stressors (Selye, 1956). Selye developed this concept in spite of his advisors and mentors cautioning him that such a pursuit would be tantamount to wasting his life.

Selye’s General Adaptation Syndrome model graphically represents a timeline against which different stressors can be charted from the short-term activities such as an athlete’s performance all the way through to one’s life (Figure 1).

Soviet sport scientists adopted Selye’s concepts and used modulated stress of training to force or allow the organism (the athlete) to adapt to the different stresses used to challenge the athlete. This was the beginning of modern training theory (Viru, 2002).

The resulting Yakolev’s Model (Figure 2) is a sine wave pattern of stress, recovery and adaptation. This pattern is repeated through the various time cycles and promotes an evolution of physical, technical, tactical and psychological qualities that together create a more complete athlete.

The X and Y axes of Yakolev’s Model succinctly summarize the process of training. Positive X represents the progressive march of time. Positive X also represents one’s basic metabolic rate or homeostasis, the theoretical balance between work and rest. The Y-axis represents a state of performance or health with +Y being adaptation to a training stressor and -Y representing fatigue or the longer-term maladaptation to a stressor as evidenced with overtraining, performance stagnation, illness or injury.

Stressors and the expenditure of effort create fatigue, dropping one to a low point, what Martin and Coe called “the Valley of Fatigue” (Figure 3). This is followed by a time of rest and recovery. If this time period is adequate there will be some form of adaptation by the body as evidenced by enhanced performance. Periodized training repeats this cycle through the forward progression of time be that days, weeks, months or years.

The 3 Boxes

Verkhoshansky taught that application of the hard-medium-easy 3-day cycle was the core of weekly training plans, but also longer four and six-week training cycles. Visually hard-medium-easy (Figure 4) is an easy concept to comprehend. The concept is more challenging in actual practice. The reasons for this are varied.

The pursuit of excellence is a multi-faceted journey. On one hand there are clear markers or traits that are necessary, if not critical. Perseverance, diligence, goal directed behaviors, personal responsibility would all make any coach’s short list. The problem becomes in trying to determine how much perseverance, diligence, etc. is productive and healthy and at what point the pursuit of these personal qualities is detrimental to development.

Compounding this dilemma is the default thinking that “more is better” or that the acceptance of “good enough” is a sign of underachievement. Adherence to either belief creates an element of doubt or an irrational compulsion that can compromise forward movement.

The three boxes have traditionally represented 65%, 80% and 95% efforts. Qualitatively these numbers can be difficult to define. Further complicating matters is that the motivated athlete often sees a 65%/easy day as “too easy” and therefore not contributory towards the larger goal. At the other extreme, the 95% effort day may be exceeded on a day an athlete feels particularly good disrupting the short-term training plan and potentially the long range plan. Decathlete coach Harry Marra espoused the modified concept of 80-90-100. Train at 80%, arrive for competition at 90% and be 100% healthy (TC#202).

Coaches and athletes that have mastered the hard-medium-easy pattern can breeze through training cycles safely and effectively. Modulated efforts execute the long range plan by applying the cyclic nature of training and progressive overload with the patience and faith necessary to both let and make something happen.

Cycling through the three boxes allows the coach and athlete to have two harder workouts per week with enough programmed rest in the weekly plan so as not to create an overtraining situation. This all hinges on whether this pair allow the easy day to be easy.

Individual sport athletes are notorious for being overtrained. Winsley (2011) reported an overtraining incidence rate between “20-30%, with a relatively higher occurrence seen in individual sport athletes, females and those competing at the highest representative levels.” When the will to succeed overrides the sense to rest, a negative spiral can develop with both short and long term consequences.

Exactly what constitutes and “easy” day is subject to different interpretations. Lasse Viren’s easy day consisted of 5-minute kilometer/8-minute mile pace (TC #198). This 8-minute per mile pace must have been grindingly slow for a 27-28 minute 10k runner, but his coach believed that this low-level cardiovascular recovery running (heartrate below 125 BPM) developed a more thorough capillary network in the body which greatly contributed to a secondary level of endurance.

Biomotor Skill Development

Frequent, if not daily, attention should be paid to the development of the five biomotor skills (speed, strength, endurance, flexibility and the ABC’s of agility, balance, coordination and skill). Biomotor skill development is a critical component of safe and long-term involvement in sport. Additionally, attention to and development of the five biomotor skills is central to the all-around concept of multi-lateral development.

Biomotor skill development also plays an important role in the four levels of sport. For the beginning athlete a broader base of development of biomotor skills creates a greater inventory of skills which can be drawn upon as one’s ability expands. Biomotor skill development can also be seen as a form of “invisible training” where the muscles, bones and other soft tissues of the body become conditioned for the stresses of varying volumes and intensities as the progressive overload demands.

With maturity and event specialization attention to the biomotor skills still plays an important role in strengthening the “weak links” within the body that the repetitive nature of technical development often demands.

Both prehab and rehab efforts can focus on biomotor skill development. The difference between the two would be the intent of the training. Prehab efforts would ultimately address all-around development of the biomotor skills. Rehab efforts would not address speed development and the attention here is given to restoration of “normal” that would be determined with return to play testing.

Progressive Overload

Progressive overload is the continual attempt to increase the work capacity of an athlete over the course of a season or career. With the application of the three boxes (hard-medium-easy) and the adaptation of the physical capabilities of the athlete the work capacity will incrementally increase over time. This assumes the training loads are appropriate for the athlete at a particular point in a career and the athlete remains healthy and injury-free.

Determination of progressive overload hinges on other factors that can either enhance or impede training. Multiple environmental conditions (heat, cold, wind, barometric pressure, etc.) can individually or collectively present challenges that could influence results. The psychological impact environmental conditions present are often overlooked as they may alternately serve to harden the will or present as “another obstacle” that can erode the will through frustration and a decreased ability to manage change.

Volume and Intensity

The leading factor for performance improvement over the last 50 years is due to increases in physical work capacity (Bompa and Haff, 2009). The ability to train more, recover from that training and successfully repeat the process over the course of time has created athletes with the capability to produce and withstand the competitive performances necessary for success in current times.

Basic to the concept of work capacity are the training factors of volume and intensity. From one’s earliest participation coaches and athletes strive to find a complimentary balance between the two concepts that in turn leads to an enhancement of both qualities.

Volume is the quantity of work done. There are numerous ways volume is quantified. Depending on one’s discipline (speed/power events or endurance) volume may be recorded in miles done or minutes run, sets and reps, technical elements performed or ground contacts completed. Results can be recorded and used as a yardstick or benchmark from which future training can be charted.

Intensity is the measure of effort. Physiologically work is the result of effort and leaves its own set of markers. The measurement of one’s heartrate provides a low tech measure to monitor effort with escalating heartrates corresponding to various effort intensities and the energy systems being utilized.

Intensity can also be modulated by the length of the rest periods in a workout. The demands of a rapid fire circuit training routine can produce a high intensity workout in a concentrated time for even the most physically gifted athlete. Conversely, longer rest periods for speed/power athletes can allow the body’s natural regeneration reaction and creatine phosphate formation to allow the athlete to more successfully complete multiple sets of resistance work.

Other measures of intensity such as Newtons (the force that gives 1 kilogram of mass an acceleration of 1 meter/second) or joules (the work done when the force on one newton moves an object one meter) both contain the element of time. Although less common, these measures may also provide useful information of the intensity of work done that can again, be used as a reference point for future efforts.

Classically it has been recommended that a season long cycle begin with a higher level of volume and a lower level of intensity. As a season progresses volume decreases and intensity increases. Seasonal volume and intensity curves graphically produce a characteristic x-pattern (Figure 5).

Volume and intensity should not be increased at the same time. This is a common mistake of a new or recently motivated athlete as opposed to a seasoned veteran. Attempts to increase volume and intensity simultaneously usually result in illness, injury or performance stagnation as the stresses produced on the body are too great to handle and is neatly summarized with the sentiment “too much, too soon.”

The Four Global Concepts

Ultimately one needs to formulate an organizational plan that encompasses the seven points discussed above. Rather than attempting to “re-invent the wheel” one can copy what Bompa called the Four Global Concepts (Figure 6) of physical development, technical preparation, tactical execution and psychological strength. This is a tried and true approach to coaching. The grid encourages identification, development and management of athletic talent over a four-year cycle. This model has been championed since the 1950’s by numerous authors (Medveyev, 1981; Kurz, 2001; Siff and Vershonshyy, 2004; Bompa, 2009; Connolly, 2017).

The Four Global Concepts allows the coach to sculpt his or her program according to a coach’s knowledge, philosophy and aspirations. There is tremendous leeway in terms of what is included. The beauty of this model is that it can accommodate a wide range of ability levels while at the same time offering a comprehensive approach to training that develops the whole athlete. (see Figure 6 for suggestions)

Further, use of the Global Concepts affords the coach the opportunity to capitalize on training time, be that the weekly, monthly or seasonal cycles. Training can be streamlined over a four-year period improving the effectiveness of the long-range training plan through the presentation of team standards, values and expectations that offer a clearly presented pathway for growth by the athlete.

When shared with the athlete the four-year plan underscores the coach’s expectations of a progressive development of the athlete’s skills via development of the athlete as a person. This concept is often marginalized or lost in the discussion of training theory.

Finally, use of the Four Global Concepts lends itself towards creating a valuable season-end coach-athlete review. Using the four categories (physical, technical, tactical and psychological) grades can be assigned to the various traits or qualities à la the Athletic Report Card (TC#93). This report card can give the athlete tangible discussion points for future goal setting with the coach, teammates or other professionals affiliated with the team such as the sport psychologist or strength coach.

The Four Levels of Sport

Training theory and periodization mean different things at different ages and stages of an athlete’s career. It helps to frame the argument if one looks at sports participation as consisting of four distinct levels of participation (Figure 7). Each level has its own goals and objectives along with its own set of challenges. Sports participation viewed in this regard allows for a more appropriate level of expectations as to what can be and should be accomplished at the individual stages of a career or throughout an athletic lifespan.

The Fundamental Stage

The Fundamental Stage is the entry level into sport. Initially one might see this as a starting point for a child, but it could also serve the sedentary adult whose middle-aged motivation has led him to a more active lifestyle.

The establishment of movement fundamentals and a skills inventory will create a background from which future efforts can be formed. Bompa’s admonishes us to not “fatigue the system” regarding the child athlete and the balance that needs to be struck between growth and development versus training and competition. His recommendations of not exceeding 65% efforts allows for activities that are not exhausting. And while these “easy” efforts would run counter to the “no-pain, no-gain” mentality it would promote the desired growth and development, at this stage, versus the more energy demanding training and competition of the mature athlete.

But what about the “new” mature athlete? Would this approach work? If one were to view the movement into a fitness lifestyle as a process this approach would be a first step in a long journey. Lifetime fitness would entail most of the training considerations noted in Figure 8. Focus and attention to these training components could be crafted so that a graduated entry into an active lifestyle could be designed safely with minimum risk of injury along with sound fundamental movement patterns that would lay a solid foundation if the transition to occasional competitive efforts becomes a desired goal.

Fitness

Physical fitness is classically defined as the ability to meet present and future physical challenges with success. This is contingent on one’s stage of life or even the stage of one’s career. A determining factor in one’s assessment of fitness is the activities of daily living (ADL’s). An athlete’s life could be filled with miles of running or hours of weight training versus a retired person’s ADL’s that include walks, golf and shopping.

Physical fitness, at least in the U.S., is defined by the aerobic paradigm and cardiovascular fitness. This is an outgrowth of the running boom of the 1980’s where the repetitive motions of running have morphed into a series of linear activities (Figure 9) that stress the cardiovascular system while often reducing or transferring the stresses of the activity from common problem areas such as the knees and low back.

The linear, straight line, sagittal plane movements bear comment. While the movement skills depicted in Figure 9 all promote cardiovascular fitness it is to the detriment of one’s lateral movements and dynamic stability. Taken to extremes these exercises promote overuse injuries and limit multi-lateral (all-around) development. Why is this a concern?

Multilateral development is a component of dynamic stability (the ability to maintain postures while moving) which are biomechanically more efficient, offer better force application and decrease injury risk. Admittedly, these are more considerations of a performance- based athlete. While training linear movements can create a beneficial effect on one’s cardiovascular fitness level they will make less of a contribution to the speed and power qualities necessary for competitive effort success.

Performance Based Training

Performance-based training is where the application of sport science and the concept of periodization intersect to produce outstanding efforts. Weekly workloads and artful manipulation of quality and quantity of work with pre-determined cycles and phases are linked together with specific goals of increasing work capacity through the artful refinement of the Four Global Concepts of physical fitness, technical preparation, tactical execution and psychological strength.

The Soviets taught that training at an elite level (performance-based training) is not a natural or healthy thing to do to the body. There is a price to be paid for the continual stresses and strains that challenge the adaptive capabilities of the body. If this is true it underscores the import of a comprehensive career management plan and development of the “whole” athlete.  The other option, a laissez-faire approach towards training, is sure to result in frustration, unrealized potential and a shortened career.

The diligent, repeated cycling through of hard-medium-easy days allows the athlete to repeatedly descend into Martin and Coe’s “Valley of Fatigue” with the realization of both the potential for harm (overtraining, injury) or that a desired benefit (resilience, adaptation) may be the result. It is a fine line that separates just enough from too much but underscores the truth of F. Scott Fitzgerald’s quote, “brave men and women play close to the line.”

The application of the Four Global Concepts therefore becomes a critical component of performance-based training as opposed to a secondary or minimal concern in the Fundamental or Fitness stages of training, respectively. Use of this model allows for a “road map” of sorts whose incremental changes can be charted, and in time, accomplished.

The beauty of the Four Global Concepts model for the performance-based athlete is that it effectively allows the coach to design a career plan that neatly organizes the training theory fundamentals discussed above (periodization, volume and intensity, progressive overload, etc.) into a comprehensive overview that can serve as a distant, yet guiding light as opposed to time spent aimlessly drowning in the minutia of day-to-day struggles or a career constantly compromised by Dick’s “outside agencies.” (Figure 10)

Prehab or Rehab – The Fourth Level of Sport

Prehab or rehab is an either/or situation. Either one does prehab preventive exercises or the unavoidable damage of countless repetitive motions eventually creates biomechanical imbalances that present with physical breakdown at the body’s weak links necessitating a period of rehabilitation. Figure 11 contrasts the differences between prehab and rehab efforts.

Prehab is a time of practice where technique can be refined (neuromuscular education) along with re-enforcing the fundamental and career long import of the various body stabilities. Any potential problem areas or weak links that may develop in response to the particular demands of an event can be addressed with exercises used to prepare key areas for these stresses.

Whole body consideration is addressed with whole body movements that promote body’s kinetic chain coordination and allow for a directed growth and development. Prehab components are proactive in nature. One engages in this activity to be better able to withstand the focused demands of event specialization and create a body that can challenge current limitations with superlative efforts.

Rehab is reactive in nature. An injury or illness has occurred and due to imbalance or neglect of prevention efforts the stresses and strains of training have broken down the weak link. Examples of the need for rehabilitation would include a gait abnormality (a limp), a technical breakdown (a decreased fluidity of movement or a decreased range of motion at a joint complex) or an instability at a joint complex. There may also be the inability to produce force due to a bone or soft tissue injury, a strained or damaged muscle or compromised stretch reflex.

Rehabilitation efforts focus on neuromuscular
re-education, a re-learning of the proper, biomechanically correct movement patterns. Attention is paid to specific restoration of pain-free function. This may entail reconditioning of specific muscles or muscle groups and address the redevelopment of the biomotor skills. Progress is measured with “return to play” testing that measures fitness (the ability to meet present and future challenges with success) to an acceptable level before pre-injury training can resume.

Ultimately rehab time is lost time or at best a holding pattern. Rehabilitation sidetracks one’s formal progression. One does not advance in the linear periodized progression. This is problematic as the “lost time” in the 10-12 year window of an athletic career can never be regained. This compromises any efforts to reach one’s full potential. This fact only serves to underscore Bompa’s earlier quote – the limiting factor in athletic development is not enough time. Time is of the essence in training.

Summary

There are multiple pieces to training theory and the periodization puzzle. To effectively employ the concepts, it is important to master the individual parts and then both artfully and skillfully combine the component parts to create an effective whole.

Over the last 15 years it has been fashionable to question the value and efficacy of periodization. Authors have designed short-term studies with volunteer participants tested with 6-week studies using the scientific method to effectively “prove” that periodization does not work (Hornsby et. al., 2020).

While these studies have checked the necessary boxes for peer reviewed acceptance with informed consent, Helsinki Protocols, a narrow list of dependent variables and statistically significant results the short timeline for these studies misses the point. Further clouding this issue is that the participants are of questionable athletic ability who participate with questionable intent. The resulting studies are more an academic exercise conducted under the guise of scientific scrutiny rather than an enlightened pioneering endeavor.

Application of the components of training theory and successful periodization planning is a long-term process accomplished with a committed team effort between the coach and athlete that takes months, if not years to realize the individual’s potential.

The fundamental training theory components detailed above offer starting points that along with implementation of the Four Global Concepts offers a workable model that can streamline the planning process and make the time, effort and energy dedicated to training more effective in both the short and long terms. 

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Terminology Defined

Biomotor skills – The development of the five biomotor skills (speed, strength, endurance, flexibility and the ABC’s of agility, balance, coordination and skill) are a means to insure multi-lateral development. It is a broad based approach towards athletic development. The skills are necessarily learned in combination yet one skill may predominate within the individual disciplines of track & field (i.e. – speed – 100m, strength – shot put, endurance – marathon, etc.).

Early specialization – It is generally accepted, with few exceptions, that early specialization stifles long-term growth and development of an athlete. The young athlete never develops the broad-based skill set that allows for the cross fertilization of thought and actions that promotes growth and makes for a more complete skill set as the athlete matures.

General Adaptation Syndrome (GAS) – Selye’s GAS describes the body’s short and long-term handling or reaction to stress. He broke this process into three stages – an alarm reaction, a period of resistance and finally, a period of exhaustion.

Invisible training – Invisible training is the use of MLD to condition the soft tissues of the body for the stresses and strains of training and competition. A broader application of this concept would be the conditioning of the various systems of the body (cardiovascular, musculoskeletal, nervous, hormonal, etc.) to withstand the give and take demands of training. Training adaptations are not visible to the naked eye.

Multi-lateral development (MLD) – MLD is a concept of developing the athlete in an “all-around” manner. This could entail a broad-based approach to developing the biomotor skills through varied activities and drills that challenge the athlete in new and innovative ways. MLD is the antithesis of early specialization.

Neuromuscular education – Neuromuscular education is the programing of movement patterns that make up the skills and sub-skills of technique. The body learns through the repetition of patterns that over time develop into technical models that are physiologically sound and or biomechanically efficient. Biomechanical efficiency affects force production, energy use, mitigates injury and enhances performance. Injury, poor fundamental training or sloppy training habits would necessitate a re-learning or neuromuscular re-education that ultimately is “lost time” in the career of an athlete.

The sagittal plane – the body moves in three planes – frontal (dividing the body into front and back), transverse (dividing the body into upper and lower) and sagittal (dividing the body into left and right). Forward and backward movements in sports move in the sagittal plane. Movements depicted in Figure 8 follow a linear path and move in the sagittal plane.

Training theory – Training theory is an all-encompassing approach to identify, manage and develop an athlete. Modern coaching actions are drawn from scientific studies, continual observation and the masterful application of knowledge by experienced coaches. Training theory would include such sub-topics as periodization, progressive overload and the four global concepts to organize the task of coaching.

Work capacity – Work capacity is the measure of the amount of effort put into sports training over the course of time. This training volume may be quantified with hours of practice, miles covered, weight lifted, technical elements completed, ground contacts and would  more than likely include multiple combinations of these measures. This training volume has increased significantly over the last 50 years.

References

• Bucciarelli R. The basics of periodization for soccer. http://www.soccerfitness.ca/wp-content/uploads/2016/12/The-Basics-of-Periodization-for-Soccer-Soccer-Fitness-E-Book.pdf#:~
• Bompa T. (1983). Theory and methodology of training. Kendall Hunt: Dubuque, Iowa.
• Bompa T and GG Haff. (2009). Periodization: theory and methodology of training. (pp. 4, 259-269). Human Kinetics: Champaign, IL.
• Connolly F and P White. (2017). Game changer: the art of sports science. Victory Belt Publishing.
• Hornsby WG, Fry AC, Haff GG and MH Stone. (2020). Addressing the confusion within periodization research. Journal of Functional Morphology and Kinesiology. 5, 68; doi 10.3390/jfmk5030068.
• Kurz T. (2001) Science of sports training. Stadion Publishing: Island Pond, VT.
• Martin D and P Coe. (1997). Better training for distance runners. Human Kinetics: Champaign, IL.
• Matveyev, L., (1981). Fundamentals of sports training. Progress Publishers: Moscow, USSR.
• Siff, M.C. (2004). Supertraining. Supertraining Institute: Denver, CO. 
• Selye, H. The stress of life. McGraw Hill: New York. 1956.
• Viru A. Early contributions of russian stress and exercise physiologists. Journal of Applied Physiology. Apr 2002. Vol 92. p. 1378-1382.
• Winsley R and N Matos. (2011) Overtraining and elite young athletes. Med Sport Sci. 2011;56:97-105. doi: 10.1159/000320636. Epub 2010 Dec 21.
• From Track Technique/Track Coach
• Ebbets R. An interview with Tudor Bompa. Track Coach #164.
• Ebbets R. What an American runner can do – interview with Jim Beatty. Track Coach #166
• Ebbets R. A Long Strange Trip -interview with Harry Marra. Track Coach #202.
• Ebbets R. The athletic report card. Track Technique #93?.
• Harkkola R. The secret of SISU and the making of Lasse Viren. Track Coach #198.