Compare aerobic and anaerobic respiration by considering oxygen use and energy release. Use exercise examples to explain why lactic acid forms in muscles and why breathing stays high afterwards to repay oxygen debt.
A scientist investigates the effect of exercise on breathing rate.
She measures the breathing rate in breaths per minute of two people, P and Q , every 5 minutes for 30 minutes.
This is her method.
- measure their breathing rate every 5 minutes while they exercise for 20 minutes
- measure their breathing rate every 5 minutes for a further 10 minutes while they recover from the exercise
The table shows her results.
Explain why the breathing rates of persons P and Q remain high for five minutes after they have finished exercising.