Keep your leg at a 90-degree angle and your knee and foot at the same height. Avoid rotating your spine at any point during the exercise. Pause at the top for two seconds before lowering your knee to the floor. Repeat 15-25 times before performing the exercises with the other leg.
Inhaled air is about 20-percent oxygen. Exhaled air is about 15-percent oxygen. Therefore, about 5-percent of breathed air is consumed in each breath. That air is converted to carbon dioxide. So, as far as how much air is actually used, human beings take in about 550 liters of pure oxygen per day. A person who is exercising uses a lot more oxygen than that.
The air that can not be exhaled is called residual volume. TV = the amount of air displaced during normal breathing. IRV = The amount of air that can be taken in forcibly â¦ beyond tidal volume Erv= The amount of that can be expelled forcibly. Vital capacity = the total amount of exchangeable air.