Biochemical Foundations of Human Vital Activity - Volkov N.I., Nesen E.N. 2000

Biochemistry of Sports
Regularities of Biochemical Adaptation in the Process of Athletic Training
Cyclical Nature of Adaptation Development in the Training Process

Adaptive Changes in the body resulting from training are phasic in nature. Regular stages in the intensification of METABOLISM/26.html">Energy Metabolism processes—observed during muscular activity and the post-work recovery period—manifest as alternating phases of recovery, a steady state, various stages of fatigue, and supercompensation. The Development of long-term adaptation involves a continuous alternation: periods of sharply increased Energy Expenditure during physical loads are followed by the activation of the genetic apparatus and enhanced Synthesis of specific Proteins, ultimately increasing the functional capacity of the trained system. To achieve a pronounced adaptive effect during training, two key conditions must be met.

First, it is necessary to ensure an adequate level of stimulus for each of the leading Functions. In most sports, performance levels are determined by a few key factors or leading functions. Because training loads that stimulate these functions may exhibit negative interactions, they should be separated in time—meaning that each individual training session should focus on loads with the same physiological impact. Therefore, to properly "work out" all leading functions, the planned training program must be divided into a series of consecutive sessions combined into a single cycle. Within this cycle, sessions should alternate so that the acute effects of each subsequent workout do not negatively impact the delayed training effect of the preceding load. For example, if sprinters perform a workout on the first day of the cycle aimed at developing alactate anaerobic power, subsequent days—while this function recovers—may involve training loads designed to enhance glycolytic anaerobic or aerobic capacity.

Second, the overall impact of physical loads within individual training sessions or microcycles must not exceed a permissible threshold, beyond which the adaptive reserve is irreparably depleted and the recovery processes in the body slow down drastically. Reaching this adaptive limit is possible even within a single training session. However, such stressful loads can trigger maladaptation due to the exhaustion of the leading function responsible for coping with that specific type of load. A more effective approach is to use submaximal training loads in terms of volume, which ensure the necessary Structural and functional changes in the body.

Fulfilling these conditions in athletic training leads to the creation of elementary (weekly) training microcycles, which typically consist of 5–7 training days. Each training microcycle achieves the necessary magnitude of stimulus across all "leading" functions required to develop Specific Adaptation to a given type of load. Depending on the predominance of certain types of loads and their sequence, each training microcycle has a strictly defined focus on developing specific functional properties and physical qualities of the athlete. Complete ADAPTATION TO A microcycle of a specific directional focus usually occurs after repeating it 3 to 4 times.

Training microcycles differ in the magnitude of the impact achieved and whether they emphasize the development of a specific leading function or physical quality. Based on their structural design, training microcycles are categorized into several types: introductory, Shock, unloading (recovery), tonic, or tapering.

Several continuously repeating training microcycles aimed at solving a specific pedagogical task and leading to specific adaptation to particular physical loads constitute individual stages of seasonal preparation—mesocycles. At each stage, the primary focus of the applied training means and Methods shifts, and consequently, the dominant physiological system responsible for adaptation also changes. Accordingly, training stages are generally classified as introductory, main (base), control-preparatory, pre-competitive, competitive, and intermediate. An example of Structuring the main training stage, featuring alternating shock and recovery microcycles, is shown in Fig. 206.

A series of training stages (from 2 to 5) sharing the same overall directional impact of the applied training loads constitutes a training period—macrocycles. In the seasonal preparation cycle for most sports, preparatory, competitive, and transitional periods are distinguished as training macrocycles. The overall dynamics of adaptation development for the leading function across individual stages and periods of the annual training cycle—where the focus of training stimuli shifts and The Nature of adaptive restructuring in the body changes accordingly—are illustrated in Fig. 207.

Every athlete has an individual limit of adaptation to specific types of physical loads. When using targeted interval loads at a given stage of preparation, The rate of adaptive restructuring in the body gradually decreases, and continuing to use this type of load no longer yields performance gains. Further development of fitness at this point is possible only by changing the Nature of the training stimulus, redirecting adaptation toward the development of other functions and qualities.

Class="center">

Fig. 206 Relationship between the permissible volume of glycolytic anaerobic loads, the increase in maximum O₂ debt indicators, and the level of maximum aerobic capacity achieved by THE START OF experimental running training

Fig. 207 Dynamics of athletic performance during the alternation of microcycles with different focuses during the main (base) training stage of short-distance runners

Fig. 208 Periodic nature of adaptation development across individual stages and periods of the seasonal training cycle

The development of adaptation to a chosen type of load over time follows a curve with a pronounced lag phase (latent phase), an acceleration phase, and a deceleration phase (Fig. 208). The duration of the lag phase is determined by the time required for a given functional system to establish dominance over other leading functions that may also contribute to adaptation. The acceleration phase reflects the increasing rate of adaptive changes in the body as the applied loads narrow in focus toward the dominant function or quality. The deceleration phase is caused by the exhaustion of the adaptive potential of the functional system driving adaptation to that specific type of load. The successive alternation of dominant factors during training ensures continuous improvement in fitness, gradually approaching the individual limit of physical performance. As this limit is approached, the rate of adaptation development progressively slows down.

The degree of adaptation mastery in interval training can be assessed by the rate of change in leading function indicators during preparation (kinetic perfection). The relationship between performance gains and changes in the training stimulus (amount of work performed) was thoroughly studied by German scientists Madorin and Mellerowicz back in 1972. In their research, four groups of subjects with very similar fitness levels trained for four weeks on a cycle ergometer using interval loads of equal intensity but varying in total volume: the first group performed about 6,000 kpm of work per week, the second about 18,000, the third about 36,000, and the fourth group about 60,000 kpm.

The effectiveness of adaptation achieved over 4 weeks of interval training was assessed by the relative performance gain per unit of work performed (per 1,000 kpm of load). The main results of this experiment are presented in Fig. 208. The figure shows that adaptation effectiveness achieved over 4 weeks of training decreases as the volume of training work increases. The highest adaptation effectiveness was observed in the group that performed the least amount of work, and it was noticeably lower in the group that performed the largest volume of loads. Based on the experimental results, the authors drew the following Conclusions:

✵ adaptation effectiveness achieved during training decreases exponentially as the volume of the performed load increases;

✵ given the same amount of completed training work, the greatest adaptation effectiveness is achieved by increasing the intensity of the load;

✵ as the level of fitness increases, the effectiveness of adaptation declines;

✵ the highest adaptation effectiveness is observed when using high-intensity training loads over relatively short periods (3 to 4 weeks), as well as during high-stress training of subjects with a low baseline performance level.

Fig. 209 Adaptation effectiveness during training with interval loads of varying volume (1–4 represent indicators over 4 weeks of interval training)

Fig. 210 Changes in the rate of performance growth in 100-m freestyle swimming among ranked athletes (1) and international master sports competitors (2) during long-term preparation

The kinetic perfection of adaptation to physical loads, i.e., the rate of development of adaptive changes in response to a specific type of training, appears to be a genetically determined property. This is evidenced, in particular, by the fact that elite athletes who have achieved high athletic mastery in their chosen discipline differ from less trained athletes in their rate of performance growth even at the Initial Stages of training (Fig. 210). Upon reaching the highest level of performance, highly qualified athletes are characterized by high stability of performance indicators under The Influence of various types of loads. This means that as athletic mastery grows, the efficiency of adaptation developing in the training process noticeably decreases. The structural and functional alterations occurring in the body under the influence of training in a chosen sport, which ensure the perfection of its adjustment to physical loads, simultaneously act as a brake on the further development of adaptation in this direction. Therefore, at The final stage of training, the search for new, non-traditional training means and methods that can ensure further growth in performance and athletic achievements acquires special significance. This problem must be taken into account when addressing the training issues of highly qualified athletes who have undergone long-term training in a chosen sport and have achieved a high degree of adaptation to the effects of conventional training means and methods.

Review Questions

1. What are the BIOCHEMICAL FOUNDATIONS OF acute and long-term adaptation?

2. Provide a biochemical characterization of "acute", "delayed", and "cumulative" training effects.

3. What are the fundamental biochemical principles of sports training?

4. What is the Specificity of the biochemical impact of applied physical loads?

5. How can training efficiency be assessed based on the dose-response relationship?

6. How to determine the most effective dosages of training load?

7. How does the supercompensation phenomenon manifest itself during repeated loads in the training process?

8. How is it best to distribute sessions of different orientations within a training microcycle?

9. How do the indicators of power, capacity, and efficiency of aerobic and anaerobic performance develop in the course of training?

10. How do acute and delayed adaptive changes interact in the body during the training process?

11. How to establish the optimal ratio of loads in the training process?

12. What conditions must be met to achieve a pronounced adaptive effect during training?