Final answer:
During exercise or active thought that requires muscle contraction for both inspiration and expiration, a forced breathing mode called hyperpnea occurs.
Step-by-step explanation:
During exercise or active thought that requires muscle contraction for both inspiration and expiration, a forced breathing mode called hyperpnea occurs. Hyperpnea involves an increased depth and rate of ventilation to meet the increased demand of oxygen. This type of breathing does not significantly alter blood oxygen or carbon dioxide levels, but it helps provide sufficient oxygen to all the body tissues.