Zones of Relative Power in Muscle Work

The zone of relative muscle work power refers to the period during which physical activity, with set parameters of power and energy threshold, maintains its intensity.

Types

Based on the relationship between the three pathways of ATP resynthesis: glycolytic, creatine phosphate, and aerobic, which are used for energy supply in muscle activity during different types of physical activity, four zones are distinguished:

1. Zone I — Maximum Power Zone: Physical activity lasts up to 20 seconds.
2. Zone II — Submaximal Power Zone: Load lasts from 20 seconds to 5 minutes.
3. Zone III — High Power Zone: Duration of physical load ranges from 5 minutes to half an hour.
4. Zone IV — Moderate Power Zone: Activity lasts more than half an hour.

In some sports, such as football, basketball, badminton, tennis, etc., power frequently changes.

Factors like age, sex, and other individual characteristics of the athlete, as well as the objective laws of muscle contraction, determine the structure of these zones.

Zone I

Examples of activities in the first zone include pole vaulting, javelin throwing, shot put, some track and field disciplines, snatch in weightlifting, and certain exercises in gymnastics. The physical load is performed in a period not exceeding 20 seconds.

Adenosine triphosphate is generated through anaerobic pathways. Initially, the creatine phosphate pathway of resynthesis is used, which is replaced by the glycolytic pathway, or glycolysis, towards the end of the physical load.

Zone II

Activities like 800-meter running, 50-meter breaststroke swimming, track cycling, and 1000-meter short-track running are examples of physical activity performed in the second zone. The duration of the physical load ranges from 20 seconds to 5 minutes.

EPOC (Excess Post-Exercise Oxygen Consumption) is 20 liters, the highest among all zones.

Initially, the creatine phosphate pathway of ATP resynthesis is activated, which is subsequently replaced by the glycolytic pathway. Towards the end, the body uses cellular respiration for energy.

Zone III

The main energy suppliers are glycolysis and cellular respiration, with an initial contribution from the creatine phosphate reaction.

Activities lasting from 5 minutes to half an hour, such as 10,000-meter speed skating for men, biathlon races, etc., belong to the third zone.

Zone IV

Activities like 20 km and 50 km race walking, marathon running, 50 km mass start in cross-country skiing, and other similar activities fall into the fourth zone.

ATP is generated through the aerobic pathway of resynthesis.

Training for Competitions

During the training period, it’s essential to focus on the predominant zone in the athlete’s sport. Considering the specificity, it’s crucial to choose physical exercises and loads that will develop the pathways of ATP resynthesis, playing a key role in the energy supply for muscle functioning.