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

Biochemistry of Sports
Biochemical Control in Sports
Objectives, Types, and Organization of Biochemical Control

During the body's adaptation to physical exertion, overtraining, or pathological states, METABOLISM undergoes changes that lead to the appearance of specific metabolites (metabolic byproducts) in various Tissues and biological fluids. These reflect functional shifts and can serve as biochemical tests or key performance indicators. Therefore, alongside medical, pedagogical, psychological, and physiological monitoring, Biochemical Monitoring of an athlete's functional state is widely used in sports.

Elite sports practice typically involves comprehensive scientific evaluations of athletes, providing complete and objective data on the functional status of individual physiological systems and the body as a whole, as well as its readiness for physical loads. At the national team level, such monitoring is conducted by multidisciplinary scientific groups (MSGs) comprising several specialists: a biochemist, physiologist, psychologist, physician, and coach.

Determining biochemical metabolic markers helps address several comprehensive assessment objectives: monitoring the athlete's functional status—which reflects the efficiency and rationality of their individual training program—tracking the adaptive changes in primary energy systems and functional reorganization during training, and diagnosing pre-pathological and pathological metabolic shifts in athletes. Biochemical monitoring also addresses specific tasks, such as identifying physiological responses to exercise, assessing the level of fitness, evaluating the appropriateness of pharmacological and other recovery AIDS, understanding The Role of energetic metabolic systems in muscular activity, and assessing the IMPACT OF ENVIRONMENTAL factors. Consequently, sports practice employs biochemical monitoring at various stages of an athlete's training.

In the annual training cycle of qualified athletes, several types of biochemical monitoring are distinguished:

✵ ongoing assessments (OA), conducted daily in accordance with the training schedule;

✵ stage-by-stage comprehensive assessments (SCA), conducted 3–4 times a year;

✵ in-depth comprehensive assessments (ICA), conducted twice a year;

✵ competition performance assessments (CPA).

Ongoing assessments determine the athlete's functional state—one of the core indicators of physical fitness—evaluate the immediate and delayed training effects of physical loads, and allow for adjustments to training loads on the fly.

During stage-by-stage and in-depth comprehensive assessments, biochemical markers help evaluate the cumulative training effect. Furthermore, biochemical monitoring provides coaches, educators, or physicians with rapid and fairly objective information regarding fitness gains, functional bodily systems, and other adaptive changes.

When organizing and conducting biochemical assessments, special attention is paid to selecting test biochemical parameters: they must be reliable or reproducible, consistent across repeated control tests, informative (reflecting The Essence of the process under study), and valid or closely correlated with athletic performance.

In each specific case, different test biochemical parameters of metabolism are selected, as individual metabolic pathways respond differently to muscular activity. Paramount importance is given to the parameters of those metabolic pathways that play a primary role in securing athletic performance in a given sport.

The Methods used to determine metabolic indicators, along with their precision and reliability, are also of critical importance in biochemical screening. Currently, sports practice widely employs rapid laboratory Methods for determining numerous (around 60) different biochemical parameters in Blood Plasma using portable devices, such as the LP-400 manufactured by the Swiss company Dr. Lange or similar instruments. Another rapid method for assessing athletes' functional state is the novel technique proposed by Academician V.G. Shakhbazov, which determines human energy status based on Changes in the bioelectrical properties of epithelial Cell nuclei depending on the body's physiological condition. This method helps detect homeostatic disruptions, fatigue, and other physiological alterations during muscular activity.

Monitoring the functional state of the body during training camps can be carried out using specialized diagnostic rapid kits for biochemical analysis of urine and blood. These are based on the ability of specific substances (glucose, protein, Vitamin C, Ketone Bodies, urea, Hemoglobin, nitrates, etc.) to react with Reagents applied to an indicator strip, causing a color change. Typically, a drop of the tested urine is applied to an indicator strip such as Glucotest, Pentaphan, Medi-test, or other diagnostic tests, and after 1 minute, its color is compared against the color chart supplied with the kit.

The exact same Biochemical Methods and parameters can be employed to address different tasks. For instance, determining blood lactate content is used to assess fitness levels, the orientation and effectiveness of applied exercises, and the Selection of individuals for specific sports disciplines.

The conditions under which biochemical studies are conducted vary depending on the objectives. Because many biochemical indicators in trained and untrained bodies do not differ significantly at rest, testing is conducted under resting conditions in the morning on an empty Stomach (physiological norm), dynamically during or immediately following physical exertion, and across various recovery periods.

Athlete evaluations involve various types of testing physical loads, which can be standard or maximal (limit-threshold).   

Standard physical loads are exercises with strictly limited volume and intensity, regulated using specialized equipment such as ergometers. The most common methods include step ergometry (stepping at varying cadences on a step or staircase of different heights, e.g., the Harvard step test), cycle ergometry (performing fixed work on a cycle ergometer), and treadmill running on a belt moving at a constant speed. Today, diagnostic complexes allow for specialized dosed physical loads, including swimming flumes, rowing ergometers, and inertial cycle ergometers. Standard physical loads help reveal individual metabolic differences and are used to characterize the body's fitness level.

Maximal physical loads are used to assess an athlete's specialized fitness level across different training stages. In these cases, exercises most characteristic of the sport are utilized, performed at the maximum possible intensity for that specific activity.

When selecting test loads, one must account for the fact that a human's physiological response to exercise can depend on factors unrelated directly to fitness levels—specifically, the type of test exercise, the athlete's specialization, the surrounding environment, ambient Temperature, time of day, and others.

Performing familiar work allows an athlete to handle a high volume of exercise and achieve significant metabolic shifts within the body. This is especially evident when testing anaerobic capabilities, which are highly specific and manifest most fully only during activities to which the athlete is adapted. Consequently, cycle ergometry is best suited for cyclists, running tests for runners, and so on. However, this does not mean cycle ergometer tests cannot be used for track-and-field athletes or representatives of other sports, as they allow for the most precise quantification of work done. Nevertheless, cyclists undergoing cycle ergometric testing will hold an advantage over athletes from other sports of the same qualification level who specialize in exercises belonging to the same power zone.

The test loads used, specific in power and duration, must match the loads utilized by the athlete during training. For example, track-and-field runners specializing in short versus ultra-long distances must perform different testing loads tailored to manifest their primary motor qualities—speed or endurance. A crucial condition for applying test physical loads is the precise determination of their power, intensity, and duration.

Test results are also influenced by ambient temperature, testing time, and health status. Lower physical performance is observed at elevated temperatures, as well as during morning and evening hours. Only fully healthy athletes should be cleared for testing and athletic training, particularly with maximal loads; therefore, a medical examination must precede all Other forms of control. Control biochemical testing is conducted in the morning on an empty stomach after 24 hours of relative rest, while maintaining consistent environmental conditions that could influence testing outcomes.

Changes in biochemical parameters induced by Physical Exercise depend on the level of physical fitness, workout volume, intensity, anaerobic or aerobic orientation, as well as the sex and age of the subjects. Following standard physical loads, significant biochemical shifts are observed in less-trained individuals, whereas maximal loads induce them in highly trained athletes. Furthermore, performing sport-specific loads during competitions or time trials can trigger pronounced biochemical alterations in trained bodies that are entirely uncharacteristic of untrained individuals.