用力呼吸 ( Forced respiration )：
Forced respiration : respiration during exercise or inhalation of CO2 is called forced respiration
用力呼吸时吸气、呼气均为主动过程：
吸气时吸气肌收缩活动加强、辅助吸气肌也参与；
呼气时吸气肌舒张、还有呼气肌参与