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

Biochemistry of Sports
Biochemical Factors of Athletic Performance
Indicators of Aerobic and Anaerobic Performance in Athletes

The most important integrative indicators commonly used to assess the power, capacity, and efficiency of bioenergetic processes are summarized in Table 32.

As noted above (see Chapter 15), aerobic and anaerobic bioenergetic processes differ significantly in power, capacity, and efficiency. The highest rate of energy production, corresponding to the maximum power of the alactic anaerobic process, is achieved during exercises lasting up to 10 s, reaching approximately 3000 J ⋅ kg^-1⋅ min^-1 in highly trained athletes. The maximum rate of the glycolytic anaerobic process is attained during exercises with a limiting duration of about 30 s and amounts to 2400 J ⋅ kg^-1⋅ min^-1. The maximum power of the aerobic process is reached in exercises lasting at least 2–3 minutes and equals 1200 J ⋅ kg^-1⋅ min^-1 (assuming an average maximal oxygen uptake of 60 mL ⋅ kg^-1⋅ min^-1). Thus, the maximum power values of the aerobic, glycolytic, and alactic processes relate as 1:2:3.

The power of the glycolytic and alactic anaerobic processes declines rapidly as exercise duration increases. This is due to the relatively low values of their energy capacity. In contrast, the aerobic process far exceeds the alactic and glycolytic anaerobic processes in capacity, because the energy substrates for oxidation in Skeletal Muscle Cell/35.html">Mitochondria include not only intramuscular carbohydrate and fat reserves, but also Blood glucose, Fatty acids, and glycerol, Liver Glycogen stores, and body fat reserves across various Tissues. If capacity is assessed by the duration of work during which the maximum rate of energy production can be sustained, the aerobic process turns out to be 10 times greater in capacity than anaerobic Glycolysis and 100 times greater than the alactic anaerobic process.

Class="center">TABLE 32. Energy criteria of physical performance in athletes

Such pronounced differences are also observed in the efficiency indicators of aerobic and anaerobic bioenergetic processes. The highest Energy Conversion Efficiency, reaching 80%, is established for the alactic anaerobic process, whereas the lowest (about 14%) occurs in anaerobic glycolysis; in the aerobic process, metabolic efficiency is approximately 60%. Data on the relative manifestation of specific bioenergetic factors in the overall physical performance of athletes specialized in various sports are presented in Table 33.

As seen from the table, each sport features its own "leading" bioenergetic factors that exert a determining influence on athletic performance. For instance, performance in long-distance swimming and cross-country skiing depends primarily on aerobic power, aerobic capacity, and glycolytic anaerobic capacity; in speed skating, on aerobic efficiency and glycolytic anaerobic capacity; in swimming, on aerobic and alactic anaerobic power; and in basketball, on glycolytic anaerobic capacity and aerobic efficiency. Thus, each sport exhibits a specific combination of bioenergetic factors that predominantly affect physical performance.

TABLE 33. Influence of bioenergetic factors on athletic performance

The specific nature of athletic performance manifestations is clearly demonstrated by data on the power and capacity indicators of aerobic and anaerobic processes in athletes of various specializations, as shown in the diagrams (Fig. 167).

The highest indicators of maximal aerobic power and capacity are observed in long-distance runners, cross-country skiers, speed skaters, road cyclists, etc. The greatest alactic anaerobic power is demonstrated by sprinters, ice hockey players, and track cyclists, whereas glycolytic anaerobic power is highest in track cyclists, middle-distance runners, ice hockey players, and Water polo players. The greatest alactic anaerobic capacity is exhibited by sprinters, basketball players, and wrestlers, and glycolytic anaerobic capacity by middle-distance runners, track cyclists, and ice hockey players.

METABOLISM/18.html">The Influence of bioenergetic factors on athletic performance varies depending on exercise power and duration. This is evident from the correlation diagrams relating maximal oxygen uptake and maximal O₂ debt indicators to athletic achievements across various running distances (Fig. 168). The highest correlation between maximal aerobic power and running performance is observed at distances of 5 and 10 km. Conversely, the maximal anaerobic capacity indicator shows a high correlation with athletic performance in short- and middle-distance running.

Fig. 167 Power (a) and capacity (b) indicators of aerobic and anaerobic processes in athletes of various specializations

Fig. 168 Correlation of maximal oxygen uptake (1) and maximal O₂ debt (2) indicators with athletic achievements at various running distances