From the standpoint of this engine analogy, the notion that improving breath function by training the diaphragm is flawed. after all, you don't become a better driver by learning how to work only the gas pedal. Most of skills you acquire in driver training have to do with coordinating the acceleration of the car with steering, braking, and awareness of your surrounding. Likewise, breath training is really accessory muscle training. Only when all the musculature of the body is coordinate and integrated with the action of the diaphragm can breathing be efficient and effective