Variables of Training

by Tudor Bompa, PhD

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Any physical activity leads to anatomical, physiological, biochemical, and psychological changes. The efficiency of a physical activity results from its duration, distance, and repetitions (volume); load and velocity (intensity); and the frequency of performance (density). When planning the dynamics of training, consider these aspects, referred to as the variables of training. Model all these variables according to the functional and psychological characteristics of a competition. Throughout the training phases preceding a competition, define which component to emphasize to achieve the planned performance objective. As a rule, emphasize intensity for sports of speed and power, and volume for endurance sports. Finally, for sports requiring intricate skills, training complexity is primary.
    Increase all components of training in proportion to the athlete's overall improvement. Carefully monitor the dynamics of such a balanced increase during all phases of the annual plan and throughout a player's athletic career.

    As a prime component of training, volume is the quantitative prerequisite for high technical, tactical, and physical achievements. The volume of training, sometimes inaccurately called the duration of training, incorporates the following integral parts:

Gymboss Timers

    Volume implies the total quantity of activity performed in training. Volume also refers to the sum of work performed during a training lesson or phase. When you refer to the volume of a training phase, specify the number of training lessons and the number of hours and days of work.
    As an athlete becomes capable of high levels of performance, the overall volume of training becomes more important. For elite athletes, there are no shortcuts for the high quantity of work they must perform. A continual increase in training volume is probably one of the highest priorities of contemporary training. High training volume has a clear physiological justification: athletes cannot physiologically adapt without it. An increasing volume of work is paramount in training for any aerobic sport or event. A similar increase is also necessary for sports requiring the perfection of technical or tactical skills. Only a high number of repetitions can ensure the quantitative accumulation of skills necessary for qualitative improvements in performance.
    Performance improves by increasing the number of training lessons and the amount of work accomplished during each lesson for all categories of sports. Recovery also accelerates as the athlete adapts to an elevated quantity of work. The amount of volume increase is a function of individual characteristics and specifics of the sport. For an elite athlete to perform adequately, at least 8 to 12 lessons per micro cycle are necessary. Also a high correlation exists between the volume of hours of training per year and desired performance. An athlete expecting to place in the top 20 in the world must perform more than 1,000 hours of training per year. Athletes in international competition ought to consider 800 hours, and national-caliber athletes require at least 600 hours of training. Finally, plan 400 hours of work for an adequate performance in regional or state championships. However, too great an increase in the work volume per training lesson can be harmful. Harre (1982) suggests that such an increase leads to fatigue, low training efficiency, uneconomical muscle work, and increased risk of injury. Consequently, if the volume per training lesson is already sufficient, it is wiser to increase the number of training lessons per micro cycle than the volume of work per lesson.
    To accurately evaluate the volume of training, select a unit of measurement. For some sports (running, canoeing, cross-country skiing, and rowing), the appropriate unit seems to be space or distance covered during training. The load in kilograms seems to be appropriate for weightlifting or weight training for strength improvement. Time, which regulates other sports (boxing, wrestling, judo, gymnastics, team sports), seems to be a common denominator for most sports, although a coach often must use two measuring units, time and distance, to express the volume correctly (i.e., to run 12 kilometers in 60 minutes).
    In training we can calculate two types of volume. Relative volume refers to the total amount of time a group of athletes or team dedicates to training during a specific training lesson or phase of training. Relative volume seldom has value for an individual athlete. This means that, although the coach knows the total duration of training, he or she has no information regarding each athlete's volume of work per unit of time. Absolute volume measures the amount of work an individual athlete performs per unit of time, usually expressed in minutes. This is a far better assessment of the volume of training athletes perform.
    The dynamics of the volume throughout the training phases vary according to the sport and its ergogenesis, the training objectives, the athlete's needs, and the competition calendar.

    Intensity, the qualitative component of work an athlete performs in a given time, is also an important component of training. The more work the athlete performs per unit of time, the higher the intensity. Intensity is a function of the strength of the nerve impulses the athlete employs in training. The strength of a stimulus depends on the load, speed of performance, and the variation of intervals or rest between repetitions. The last, but not the least, important element of intensity is the psychological strain of an exercise. Muscular work and CNS involvement through maximum concentration determine intensity during training or competition. It is important to acknowledge the psychological element of an exercise and admit that even sports requiring a low level of physical exertion, such as shooting, archery, and chess, have a certain level of intensity.
    You can measure intensity according to the type of exercise. Exercises involving speed are measured in meters/second (m/s) or the rate/minute of performing a movement. The intensity of activities performed against resistance can be measured in kilograms or kgm (a kilogram lifted 1 meter against the force of gravity). For team sports the game rhythm determines the intensity.
    Intensity varies according to the specifics of the sport. Because the level of intensity varies in most sports and events, establish and use varying degrees of intensity in training. Several methods are available to measure the strength of the stimuli and thus the intensity. For example, with exercises performed against resistance or exercises developing high velocity, use a percentage of the maximum intensity, in which 100% represents best performance. In a 100-meter dash, however, best performance signifies the mean velocity developed over that distance (i.e., 10 meter/second). The same athlete may generate a higher velocity (i.e., 10.2 meter/second) over a shorter distance. I regard this velocity as 105% of maximum and include it in the table of intensities (table 4.1). For exercises performed against resistance, 105% represents a load that the athlete cannot move through the whole range of movement, but may attain isometrically. According to this classification of intensities, a distance runner (i.e., 5,000 or 10,000 meters) may train at 125% or more of the maximum, because the maximum is his or her race pace.

    An alternative method of evaluating intensity is based on the energy system used to fuel the activity. This classification (Astrand and Saltin 1961; Farfel 1960; Margaria, Ceretelli, Aghemo, and Sassi 1963; Mathews and Fox 1971) is most appropriate for cyclic sports (table 4.2).


    Intensity zone one places a strong demand on the athlete to reach higher limits in activities of short duration, up to 15 seconds. These activities are extremely intense, as demonstrated by rapid movement and a high mobility of the information reaching the CNS. The short duration does not allow the autonomic nervous system (ANS) to adapt, so the cardiovascular system does not have time to adjust to the physical challenge. The physical demand of sports specific to this zone (i.e., 100-meter dash) requires a high flow of O2 which the human body cannot provide. According to Gandelsman and Smirnov (1970), during a 100-meter dash, O2 demand is 66 to 80 liters per minute. Because the O2 stored in the tissue does not meet the athlete's needs, he or she may encounter an O2 debt up to 80 or 90% of that necessary for a fast race. This O2 debt is repaid by using extra O2 after the activity, allowing replenishment of ATP-CP stores used during the race. Continuing such activity may be limited by the O2 supply within the athlete, the amount of ATP-CP stored within the muscle cells, and the athlete's ability to withstand a high O2 debt.
    Zone two, the maximum-intensity zone, includes activities of 15 to 60 seconds (i.e., 200and 400-meter run, 100-meter swim). Velocity and intensity are maximum, straining the CNS and locomotor systems and diminishing the ability to maintain a high velocity longer than 60 seconds. The energetic exchanges within the muscle cells reach extremely high levels, yet the cardiorespiratory system has insufficient time to react to the stimulus and is, therefore, still at a low level. The athlete encounters an O2 debt up to 60 to 70% of the energy requirements of the race. The athlete derives energy predominantly from the ATP-CP system with a low lactic acid (LA) component. The O2 system does not contribute significantly to the energy requirement, because it participates primarily during exercises of 60 seconds or more. It is also significant that energy demand for one event in this zone, the 400-meter run, is among the highest.
    Zone three, also called the submaximum zone, includes activities of 1 to 6 minutes in which both speed and endurance play dominant roles (i.e., 400meter swim, canoeing, rowing, 1,500-meter run, and 1,000to 3,000-meter speed skating). The complex nature of these sports and drastic physiological changes (i.e., a heart rate up to 200 beats per minute and a maximum blood pressure of 100 millimeter Hg), hardly may be prolonged more than 6 minutes. Following a race, the athlete may have an O2 debt of 20 liters per minute and the LA may be up to 250 milligrams (Gandelsman and Smirnov 1970). Under such circumstances the body reaches a state of acidosis, in which it accumulates much more LA than the normal balance (pH7).
    The athlete adjusts to the rhythm of the race quickly, especially a well-trained athlete. Following the first minute of the race, the O2 system helps produce energy and dominates the second part of the race. At the finish, the athlete accelerates the pace. This extra strain pushes the circulatory and respiratory compensating mechanisms to physiological limits and also demands maximum energy production from anaerobic glycolysis as well as the aerobic system, resulting in a high O2 debt. The body calls on both the LA and aerobic systems to produce the energy required. The percentages of each depend on the event or sport.
    Zone four, the medium intensity zone, challenges the athlete's body with activity for up to 30 minutes. Events such as 800and 1,500-meter swim, 5,000and 10,000-meter run, cross-country skiing, walking, and long-distance events in speed skating are included. The circulatory system accelerates considerably and the cardiac muscle is stressed over a prolonged time. During the race, the blood O2 saturation is in deficit (hypoxia), or 10 to 16% below the resting level (Gandelsman and Smirnov 1970). Aerobic energy is dominant (up to 90%), although at the beginning and finish of the race athletes use the anaerobic system as well. Pacing and energy distribution throughout the race are important for athletes involved for a long duration.
    Zone five includes activities in which the intensity is low but the volume of energy expenditures is great, as in marathon running, 50-kilometer crosscountry skiing, 20- and 50-kilometer walking, and road racing in cycling. This zone is a difficult test for athletes. The extension of work leads to depleting glucides (hypoglycemia) in the bloodstream, a burden on the CNS. The circulatory system is in high demand and heart hypertrophy (a functional enlargement of the heart) is a common characteristic and a functional necessity for athletes competing in these sports and events. These athletes have a high ability to adapt to hypoxia, and following a race often experience a blood O2 saturation between 10 and 14% below resting level (Gandelsman and Smirnov 1970). The high and prolonged demand makes recovery slow, sometimes up to 2 or 3 weeks, which is one reason why these athletes do not take part in many races (3-5) per year.
    For the second and third zones of intensity, perfecting aerobic endurance, uniformly distributing energy, and self-assessing abilities throughout the race are among the determining factors of success. The physiological nature of self-assessment depends on perfecting the function of sensory organs. This is the specialized part of the nervous system that controls the body's reaction to the external environment and, therefore, the development of so-called time, water, track, ball, or implement sense. Time sense comes from rhythmical impulses from the proprioceptors of the muscles and tendons, which repeat at different time intervals. Experienced boxers, runners, and swimmers develop a sense of the time remaining in a round, split times, or the time performed in a race, based on the muscles' sensors. All these senses, with the sense of fatigue, supply information to athletes regarding the state of their bodies and assist in adapting to the training or race session and external environment.
    During training, athletes experience various levels of intensity. The body adapts by increasing physiological functions to meet the training demand. Based on these changes, especially heart rate (HR), the coach may detect and monitor the intensity of a training program. A final classification of intensities, on the basis of HR, is suggested in table 4.3 (Nikiforov 1974).


    To develop certain biomotor abilities, the intensity of a stimulus must reach or exceed a threshold level beyond which significant training gains take place. Hettinger (1966) revealed that for strength training, intensities less than 30% of maximum do not provide a training effect. For endurance sports (cross-country skiing, running, rowing, swimming), the threshold HR beyond which the cardiorespiratory system will experience a training effect is suspected to be 130 beats per minute (Harre 1982). This threshold varies among athletes due to individual differences; thus, Karvonen, Kentala, and Mustala (1957) proposed that it should be determined by the sum of the resting heart rate plus 60% of the difference between maximum and resting heart rates.


HRthreshold = HRrest + .60(HRmax HRrest)


    Thus, the threshold HR depends on the resting and the maximum HR. Furthermore, Teodorescu (1975) advocates that an athlete should employ stimuli in excess of 60% of his or her maximum capacity to achieve a training effect.
    Low-level loads or exercises in training lead to slow development, but ensure sufficient adaptation and consistency of performance. High-intensity exercises result in quick progress, but lead to less stable adaptation and a lower degree of consistency. Using only intensive exercises is not the most effective way to train, and alternating training volume and intensity is necessary. The high volume of low-intensity training athletes experience during the preparatory phase provides a foundation for high-intensity training and enhances performance consistency.
    In training theory, there are two types of intensities: (a) absolute intensity, which measures the percentage of maximum necessary to perform the exercise; and (b) relative intensity, which measures the intensity of a training lesson or microcyc1e, given the absolute intensity and the total volume of work performed in that period. The higher the absolute intensity, the lower the volume of work for any training lesson. Athletes may not repeat exercises of high absolute intensity (greater than 85% of maximum) extensively in a training lesson. Such training lessons should be no more than 40% of the total lessons per microcyc1e, with the remaining lessons using a lower absolute intensity.

Relationship Between Volume and Intensity
    Athletic exercise usually involves both quantity and quality; therefore, it is difficult to differentiate between them in training. For instance, when a swimmer sprints, the distance and time of the event represent volume, and the velocity of performance indicates intensity. Placing different relative emphasis on these components in training yields different effects on the body's adaptation and training status. The higher the intensity and the longer it is maintained, the higher the energy requirements and the more stress on the CNS and athlete's psychological sphere.
    Swimming long distances may be possible if intensity is low, but the athlete may not maintain maximum velocity beyond competition distance. Decreasing a sprinter's training intensity by 40% may allow him or her to increase work volume by 400 to 500%. Consequently, it appears that the efficiency with which the athlete can perform work of reduced intensity may substantially elevate the volume (i.e., number of repetitions). Of course, such a drastic increase in volume capacity would not prevail for an endurance athlete (long-distance runner, skier, swimmer) if the intensity decreases from his or her maximum since this already scores low on the absolute scale. Rather, to facilitate an equivalent (400-500%) increase in volume, measure the 40% decrease in intensity from the highest supermaximum load the athlete can handle.
    Ozolin (1971) exemplifies accurately the relationship between the volume and intensity of training during one year for sports with varied intensity requirements. High jumpers spend approximately 2 hours on jumps with a full approach; pole vaulters 3 hours; triple jumpers 10 to 12 minutes; gymnasts (high bar combinations) 6 hours; and long-distance runners 70 to 100 hours (for repetitions close to the competition's speed). The remaining time they dedicate to other exercises that develop the abilities required by that particular event. You can use a completely different approach for team sports, boxing, wrestling, and martial arts, in which a standard duration of competition determines the relationships between volume and intensity.
    Determining the optimal combination of volume and intensity is a complex task and usually depends on the specifics of the sport. It is simpler in sports with objective assessment methods. For instance, in canoeing the volume is based on the distance covered in training, and the intensity is expressed by the velocity at which the athlete performs a given distance. In other sports, such as team sports, gymnastics, and fencing, consider the total number of actions, elements, repetitions, their distance, and the speed at which the athlete performs them in defining the accurate proportions between the training components. Often, however, you can use the duration of a training lesson or the number of repetitions of certain skills to calculate the volume. Although not accessible to most coaches, computing the energy expenditure may be a more accurate method of assessing the weight you place on either the volume or intensity.
    Heart rate (HR) is often used as an indicator of the level of work. This method may suffice for beginners; however, elite athletes do not benefit as much from it because training involves all body functions, and change in HR is just one of many reactions. Using HR as the only method could, therefore, restrict athletes from employing the optimum training stimuli, and consequently affect the improvement rate. Using HR as a method of assessing the recovery rate between training lessons may be of more assistance in estimating the work and the athlete's reaction to it.

Dynamics of Increasing the Volume and Intensity
    The amount of work current international-class athletes perform was inconceivable in the 1970s or 1980s. Eight to twelve or even more training lessons per week of 2 to 4 hours each are considered normal. Most coaches are concerned with maximizing the athlete's free time for training. As suggested in chapter 2, add components progressively and individually. Elevate training sessions in steps. A session that was optimal in one training cycle may be
inadequate in the next, because its intensity does not reach the threshold and provoke the required training effect. An optimal session produces optimal body adaptation. Thus, an optimal session must relate to the index of effort capacity; otherwise, it may be either too weak or too powerful. The athlete accumulates the index of effort capacity in qualitative steps as a result of quantitative accumulations of work and his or her adaptation to it. During training, the athlete's adaptation and the index of work capacity increase periodically in steps and not in a straight line. Coaches need a great deal of patience to wait for the expected improvements from their training programs.
    The best progression for increasing the volume and intensity of training is as follows:

Volume of Training

Intensity of Training

    The dynamics of intensity used in training depend on the following three factors: the characteristics of the sport; the training environment; and preparation and the athlete's performance level.

    The characteristics of the sport. For sports in which maximum effort determines performance (weightlifting, throwing, jumping events, and sprinting), the intensity level during the competition phase is usually high, between 70 and 100% of the total amount of work in training. For sports in which skill mastery defines the performance (figure skating, diving, synchronized swimming), athletes rarely use high intensity. According to Ozolin (1971), the average intensity such sports use is a medium level. On the other hand, the intensity of training in team sports is complex, because the rhythm of the game is fast and the intensity alters continually between low and maximum. To meet such requirements, a training program should include some high and a continuous variety of intensities.
    The training environment. For example, increase training intensity by crosscountry skiing on wet snow, running on sand or uphill, or dragging an object while swimming or rowing. Rivalry between athletes or the presence of spectators may elevate the intensity as well.
    Preparation and the athlete's performance level. The same training content for athletes of various preparation levels or performance capabilities may represent a different intensity for each. What may be medium intensity for an elite athlete may be maximum intensity for a prospective athlete. Although athletes of various preparation levels may train together, the coach's program must differ to meet each athlete's needs.
    Elevate intensity by increasing the intensity during a lesson or phase of training, or by increasing the density of a training lesson. Obviously, the coach should emphasize the first mode because it increases the individual's potential according to the specifics of the sport or event. The coach should use the second method mainly to increase the total means of training, aiming at developing intensity, general physical preparation, or cultivating specific endurance.
    As suggested, the HR method can help calculate training intensity. By using the HR method as an objective measure, a coach may be able to compute overall intensity (OI) in training as an expression of the total demand an individual experiences during a lesson. You can calculate the OI by using the following equation proposed by Iliuta and Dumitrescu (1978):



    PI stands for percentage of partial intensity and VE for the volume of exercises. Because we must calculate the percentage of partial intensity first, we can use the following equation:


    HRP is the heart rate resulting from performing the exercise for which we are calculating partial intensity, and HRmax stands for the maximum heart rate the athlete achieves in performing the sport.
    The dynamics of volume and intensity are also a function of the dominant biomotor ability in a sport. For sports dominated by either speed or strength, emphasize intensity for progress, especially during the competitive phase. For endurance sports, volume is the main element of progression in a given phase, with intensity playing a much lesser role. Thus, it appears that volume and intensity are inversely proportional. Intensity increases only as volume decreases.
    For training content, a high absolute intensity should prevail for exercises of less than 2 minutes. At 2 minutes, the ratio between the anaerobic and aerobic energy systems is equal, or 50:50 (Astrand and RodahI1970). For sports that last approximately 2 minutes, emphasize volume and intensity equally. The importance of the aerobic energy system, however, is evident even in the first minute of a race (Mader and Hollmann 1977). Therefore, events of less than 2 minutes still require emphasis on volume in training, especially during the preparatory and early competitive phases. Over the 2-minute zone, aerobic power is evidently dominant; therefore, athletes should emphasize volume of training for sports that last longer than 2 minutes. I discuss the volume and intensity of training further in part II, chapter 8 (the annual plan).

Rating the Volume and Intensity
    The human body adapts and improves in direct relationship to the type of stimuli it experiences. The work the athlete performs in training is the cause, and the body adaptation is the effect. The optimal stimuli results in an optimal training effect. To achieve an optimal training effect, plan training programs specific to the sport and prescribe them in an appropriate dose. Set the quantity of work the athlete performs in a training lesson according to individual abilities, the phase of training, and a correct ratio between volume and intensity. If you properly administer the training dosage, correct athletic development will result, leading to an adequate degree of training (the physical and psychological level in a training phase). In training there are two forms of dosage: external and internal (Harre 1982).
    The external dosage, or load, is a function of training volume and intensity. To construct a correct training program, correctly assess the intimate characteristics of the external rating, which includes volume, intensity, density, and frequency of stimuli. Because these components are simple to measure, you can rate them easily. The external dosage usually elicits physical and psychological reactions from the athlete. These individual reactions are the internal dosage, or load, and they express the degree and magnitude of fatigue the athlete experiences. Each component of the external dosage affects the size and intensity of the internal dosage.
Applying the same external dosage does not always produce similar internal reactions. Since the internal dosage is a function of the individual's athletic potential, you can estimate its reaction in general terms only. An adequate training diary and periodic testing may facilitate reading internal reactions. The external dosage may be affected by circumstances such as the opponent's athletic caliber, equipment. facilities, environmental conditions, and social factors.

Relationship Between Volume and Adaptation
    Application of the correct dose of training results in anatomical, physiological, and psychological changes in the athlete. Positive changes from systematic training show adaptation to various stimuli. A high correlation exists between adaptation and dosage in training.
    The adaptability processes occur only when the stimuli reach an intensity proportional to the individual's threshold capacity (Harre 1982). A high volume of work without a minimal intensity (for example, less than 30% of maximum) does not facilitate adaptation, because a higher level is required to initiate such adaptation. It is possible, however, to exceed optimal stimulation by demanding too much work from the athlete or by miscalculating the volume-intensity ratio. In this case, adaptation decreases, leading to performance stagnation or even regression. Adaptation results from a correct alternation between stimulation and regeneration, between work and rest.
    The process of adequately adapting to training and competitions increases the athlete's degree of training, correct peaking, and physical and psychological improvement. The effects of a standard dosage and stimulus diminish after a while, resulting in modest performance; therefore, increase the external dosage periodically (as suggested by the principle of progressive increase of the load in training). Furthermore, if you reduce the stimulus, the training effect diminishes, resulting in an involution phase. The benefits of training may also diminish if you interrupt training too long. For instance, if the transition phase is too long or if it includes totally passive rather than active rest, all improvements obtained from the preparatory and competitive phases disappear. This requires the athlete to start training for the next preparatory phase at a low level.

FROM: PERIODIZATION, Chapter 4 by Tudor Bompa, PhD

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