The factors that affect vital capacity are :
Explanation:
Vital capacity is the maximum amount of air that a person can exhale once he has filled his lungs with maximum air. So, it is like maximum exhalation after maximum inhalation by a person.
Vital capacity is also equal to Forced Vital Capacity.
Lung usually have their maximum capacity in early adult days and this capacity reduces as the person grows older. So age is the prime factor in this.
A female with same age and height as that of male will have 10-12% less vital capacity than him. So sex is another reason which determines vital capacity.
Person with more height has more vital capacity. This is because lungs capacity is closely related to the third power of person's height.
Person suffering from obesity will have compressed diaphragm, lung and chest cavity , so their vital capacity will be less. So we can say body mass affects vital capacity.
Last factor, ethnicity, is yet to be understood clearly as there is not much evidence of this.
