What can one contract when exhaling forcibly?

When exhaling forcibly, one can contract various muscles, particularly the abdominal muscles, diaphragm, and intercostal muscles. This forceful exhalation can also lead to potential issues such as hyperventilation, which may result in dizziness or lightheadedness due to reduced carbon dioxide levels in the blood. Additionally, if done excessively, it can strain the respiratory muscles or lead to respiratory complications.