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

Biochemistry of Sports
Biochemical Factors of Athletic Performance
The Impact of Training on Athletes' Performance

The bioenergetic factors underlying athletic performance can improve significantly through training. As shown in Fig. 169, which illustrates the dynamics of various bioenergetic indicators during long-term training in young swimmers, the most pronounced and rapid training-induced gains—reaching 80–90% of baseline values—are observed in maximal oxygen uptake (VO_2max). Less pronounced increases, not exceeding 50% of baseline, occur in "excess" CO₂ output and maximal anaerobic power, while the lowest rates and magnitudes of improvement are found in maximal Blood lactate accumulation and the anaerobic threshold.

This pattern of changes in bioenergetic indicators during training reflects the general law governing The Development of long-term adaptation: power indices improve first, followed by bioenergetic capacity indices, and finally by bioenergetic efficiency indices. Upon cessation of training, deadaptation proceeds in the reverse order: efficiency indicators decline first, followed by capacity indicators, and last of all, the power parameters of bioenergetic processes.

With targeted training, the highest rate of development and the most sustained peak levels are characteristic of bioenergetic parameters that determine endurance or overall aerobic capacity. Considerably slower to respond and less enduring at maximal levels are the biochemical and physiological markers underlying speed, anaerobic endurance, and speed-strength qualities, as confirmed by differences in bioenergetic criteria among athletes of varying performance levels (Table 34). It should be noted that the trainability of individual bioenergetic parameters varies. For instance, in novice endurance-trained athletes, VO_2max is approximately 40–45 mL ⋅ kg^-1⋅ min^-1, whereas in elite athletes it reaches 80–90 mL ⋅ kg^-1⋅ min^-1. Consequently, under METABOLISM/18.html">The Influence of systematic long-term training, aerobic power indices can double, while aerobic capacity indices may improve more than fourfold (see Table 34).

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Fig. 169 Dynamics of growth indicators for various bioenergetic Functions during long-term training in young swimmers

TABLE 34. Improvement of bioenergetic process indicators under the influence of long-term athletic training