Exercise intensity and maximum oxygen uptake heart rate

I believe that many people are not familiar with maximum oxygen uptake, but for athletes, maximum oxygen uptake does have a direct and close connection. Generally speaking, maximum oxygen uptake refers to the amount of oxygen that the human body can inhale when the exercise intensity reaches the limit. It is an important indicator for measuring athletes. Below, we will introduce in detail the factors that determine maximum oxygen uptake.

1. Age and gender factors

The VO2Max values ​​between male and female teenagers (12-13) differ by about 7%. When they are 20-29 years old, the difference between male and female is about 39%. Men generally reach their VO2Max peak at the age of 18 to 20 and can maintain it until around 30 years old; women reach their peak at the age of 14 to 16 and can generally maintain it until around 25 years old. After that, VO2Max will decrease with age, at 2% per year for men and 2.5% per year for women. There are significant differences in VO2Max between men and women. The values ​​for men are larger, especially the absolute values ​​of VO2Max are more obvious than the relative values. The absolute values ​​of women are 10% lower than those of men. The average difference between the relative values ​​of VO2Max of men and women is about 10.4ml/kg/min.

2. Genetic factors

It is greatly influenced by genetic factors. In 1971, when Chrysolas studied 25 pairs of 7-13 year old twins (10 pairs of monozygotic twins and 10 pairs of dizygotic twins), he found that the heritability of VO2Max was 93.4%. Research by many scholars such as Hgabegr also pointed out that VO2Max is closely related to genetics, with the heritability reaching about 80% to 90%. Trainability, that is, the possibility of improving VO2Max through training, is relatively small, generally 20% to 25%. When children are 11 to 12 years old, their VO2Max values ​​have the highest correlation coefficient with those of adults.

3. Training Factors

Differences in physical fitness and training levels have a great impact on Vo2max. Long-term systematic endurance training can improve vo2max levels. Davis conducted a study on people who underwent systematic training and found that the subjects' Vo2max could be improved by 25%, indicating that Vo2max can be improved to a certain extent through training. Athletes in endurance events such as cross-country skiing and long-distance running have the highest Vo2max, which is significantly higher than athletes in non-endurance events and untrained people.

Exercise training can cause an adaptive increase in the number of midline hinges in skeletal muscle and myocardial cells, thereby enhancing aerobic metabolic capacity; it can lead to an increase in the capillary/muscle fiber ratio, which is beneficial to the oxygen uptake of muscle cells and increases the maximum oxygen uptake. In the process of training-induced increase in VO2Max, the increase in Vo2max in the early stage of training mainly depends on the increase in cardiac output; the increase in Vo2max in the later stage of training mainly depends on the increase in the ability of muscle tissue to utilize oxygen. It can be seen from this that training can improve the Vo2max level, but more importantly, it can improve the utilization rate of one's Vo2max. The plasticity of the latter is higher than the former. Sports practice has also proved that the size of Vo2max is closely related to the athletic performance of endurance events.

(IV) Environmental factors

When athletes are stressed in a hot environment, HR increases significantly. In order to dissipate heat, part of the blood flows to the skin, the blood flow to the exercising muscle groups is relatively reduced, and the blood lactate concentration increases. As a result, both AT and Vo2max decrease. Therefore, high temperature environment is a limiting factor for exercise load. The human body's moderate increase in red blood cells in the plateau hypoxic environment can maintain a higher blood oxygen level and maximum aerobic capacity. However, excessive increase in red blood cells will lead to a significant increase in blood viscosity, affecting the oxygen transport process. When the red blood cells are >50%, it will lead to a decrease in Vo2max and reduced exercise capacity. For people or animals acclimated to a hypoxic environment, the density of capillaries in muscle tissue increases, the myoglobin content increases, the number of mitochondria increases, and the activity of oxidases in mitochondria increases, which increases the oxygen utilization rate of tissue cells and increases vo2max.

(V) Test error

Test Error The reason for the Vo2max test error is that the judgment standard used is too wide or too strict.

(VI) Impact of body fat percentage

Body fat percentage, which is the percentage of body fat to body weight, is an important indicator of body composition. A body fat percentage of 12%-15% is more beneficial to your health. Excessive adipose tissue causes a large amount of fat to accumulate in the body, leading to weight gain and a relative decrease in oxygen consumption per unit area, which affects the level of Vo2max. Aerobic exercise can promote the improvement of cardiopulmonary function and body metabolism, and can also reduce the fat tissue in the body. The appropriate reduction of fat tissue can increase Vo2max, which is beneficial to improving the level of cardiopulmonary function.