In humans, aerobic respiration requires oxygen to give the body energy. Anaerobic respiration does not require oxygen, and tends to occur in humans for short periods of time during strenuous physical activity (for example, sprinting exercises or deadlifting).
Almost all organisms undergo aerobic respiration. In humans, aerobic respiration occurs all the time, and provides energy for the body to perform basic processes like growth, tissue repair, movement and so on.
The basic form of the aerobic respiration equation is:
Glucose + Oxygen ' Carbon Dioxide + Water + Energy.
The more detailed, balanced chemical equation for aerobic respiration is:
C6H12O6 + 6O2 ' 6CO2 + 6H2O + Energy.
When an organism, such as yeast, runs out of oxygen, it produces ethanol instead of water; similarly, when human muscles run out of oxygen, they produce lactic acid instead of water. Ethanol and lactic acid are poisonous to yeast and humans, respectively, which is why anaerobic respiration cannot continue indefinitely in either organism.
The basic form of the anaerobic respiration equation is:
Glucose ' Ethanol + Carbon Dioxide + Energy.
The balanced chemical equation for anaerobic respiration is:
C6H12O6 ' 2C2H5OH + 2CO2 + Energy.
According to the Doctor's Exercise online journal, a combination of aerobic and anaerobic activities is most healthful, as aerobic exercises benefit the cardiovascular and circulatory system, while anaerobic exercises build muscle and bone. The following are common examples of aerobic and anaerobic activities:
Aerobic: Treadmills, exercise bicycles, jogging, aerobics (including dancing to music and step dancing)
Anaerobic: Weightlifting, machines that offer resistance, dumbbells