The Valsalva maneuver is defined as "attempted exhalation against a closed airway" or "The effort to breathe out forcibly while the mouth and nose are firmly closed or the vocal cords pressed together".
Some breathing practices involve pushing air out against resistance, such as ujjayi breath in yoga or the slow, controlled exhale recommended by some weightlifting coaches. This can be done by partly closing the glottis while exhaling, or by firmly exhaling through the mouth with lips slightly open, as if one were whistling. Unlike the definitions above, the patient does not have a fully closed airway and is still taking in oxygen. But subjectively, this kind of breathing feels like it's raising intrathoracic and eustachian pressure in the same way as Valsalva.
Does forcefully exhaling against resistance have similar physiological effects to the Valsalva maneuver? Are there differences caused by the fact that the patient is still breathing, or by the fact that this maneuver can be maintained and repeated for much longer than a "strict" Valsalva?