Most important for the human body is the cardiorespiratory system which can improve the aerobic gymnastics. The aerobic capacity of an individual is reflected in the maximum oxygen uptake, i.e. the maximum amount of oxygen that the tissues of a person can consume during exercise (VO2 max).
Just like not all people are the same, not all organisms have the same ability to transport oxygen from the atmosphere in their tissues as they do not have the same ability to produce muscular energy. This is the difference between a buff and an untrained person because if a person inhales 10 liters of oxygen and exhales 8 liters the difference in inhalation and exhalation is 2 liters which is the number of liters that took advantage of the body for its actions. The greater the difference between the inhaled and exhaled oxygen is the greater the VO2 max and therefore greater aerobic capacity of the person and thus the better the cardiorespiratory system.
Aerobic capacity is lower in women than men. The biggest difference in aerobic capacity between the sexes is observed at the age of 20 years and at the rate of 30%. The low aerobic capacity of women is due to decreased binding capacity and oxygen transfer due to the lower density of hemoglobin. Research has shown that a 50 year old athlete has a better aerobic capacity than a 35 year or 40 year old who does not play sports. Also a 70 year old who never stopped exercise has aerobic capacity then can be compared to even 20 years olds who are not working out. So we conclude that exercise and even aerobic makes us feel quite younger and its results will appear in our body.
Appropriate exercises for improving aerobic capacity and of course our cardiorespiratory system is running, swimming, cycling and brisk walking or jogging.