CHANGES DURING EXERCISE
Key changes during exercise
- The lumin of the arteries supplying the muscles dilate
- Breathing rate increasing and gets deeper
- Heart and pulse rate increase
- Sweating occurs
Anaerobic respiration is when your muscles produce energy without oxygen.
If you exercise for a long time your muscles start to fatigue. This means that they don't contract as strongly as they normally do and this causes muscle cramp.
Most of the time muscles get the energy to contract from aerobic respiration. However, if you suddenly start exercising vigorously or if you exercise vigorously for some time, your muscle cells may not be able to get enough oxygen to keep contracting at the necessary rate.
If oxygen levels are low…