All adults in the United States are encouraged to get at least 30 minutes a day of exercise most days of the week, according to recommendations by the American Heart Association. Exercise relies on a complex set of reactions within your body to provide the work and energy needed to perform physical activity. One of the main players in this series of reactions is the lungs, especially in relation to oxygen and carbon dioxide.

Exercise Energy Consumption

Carbon dioxide output relies largely on the amount of energy your body is using. Your body constantly needs energy for basic operations such as your heart beat and digestive system, which means carbon dioxide is always being produced as well. However, as you exercise, you significantly increase the energy needs in your body as your muscles work at an accelerated and more intense pace.

Increase in Oxygen

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To create new energy, oxygen must be present in the bloodstream. The more energy being used through exercise, the more oxygen is needed to create new energy. To meet these needs, your body initiates an increase in both your respiratory rate and your heart rate. The increased respiratory rate increases how much oxygen is inhaled into the lungs and transferred into the bloodstream. The increased heart rate speeds up how quickly oxygen can be transported to the cells for energy creation.

Carbon Dioxide Production

Once oxygen makes it to the needy cell, it's combined with broken-down nutrients from the foods you've recently consumed and created into energy through a process called aerobic respiration. However, as the cell creates energy, it also creates byproducts of heat, water and carbon dioxide. While the excess heat is used to maintain body temperature or is released from the body through sweat, the water exits the body through urine, sweat or through your breath. This leaves carbon dioxide.

Removal of Carbon Dioxide

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Your body has no real use for carbon dioxide. As such, this waste product is transferred back into your bloodstream. The carbon dioxide is diffused into the blood plasma where it is taken by your veins back to the lungs. The carbon dioxide diffuses from the bloodstream into the lungs, where it is exhaled out of the body. The increased heart and respiratory rate also assists in this process, as carbon dioxide is produced at a much higher rate during exercise and needs to be pulled from the body at a faster rate.