Response to exercise

During exercise, the body needs more energy to support increased muscle activity. To meet this demand, the rate of respiration increases, and the body attempts to take in more oxygen to fuel aerobic respiration.

1. Increased Breathing Rate and Volume: Breathing rate and breath volume increase to allow more air into the lungs, providing more oxygen for diffusion into the blood and enabling the removal of carbon dioxide.

2. Increased Heart Rate: The heart beats faster to transport oxygenated blood to the muscles more quickly, while also transporting carbon dioxide from the muscles back to the lungs.

3. Anaerobic Respiration: If there isn’t enough oxygen available for aerobic respiration, anaerobic respiration occurs in the muscles. This incomplete breakdown of glucose leads to a build-up of lactic acid, resulting in an oxygen debt. The accumulation of lactic acid causes muscle fatigue and pain, and after prolonged vigorous activity, muscles may become fatigued and stop contracting efficiently.

The body's response to exercise can be investigated by measuring heart rate, breathing rate, or pulse rate after a period or intensity of exercise. Breath volume can also be measured using a spirometer. Changing the duration or intensity of exercise (independent variable) allows us to see its effect on heart rate, breathing rate, or breath volume (dependent variables). All other conditions should be kept constant as control variables.

The oxygen debt (Higher tier only)