I’m sure this is far more common than you can imagine. I think of “stress incontinence” as any physical stressor which differs from the body’s lax resting state. That can include exercising, standing up/sitting down, vomiting, passing gas, et al.  It’s simply not socially acceptable to align the phenomenon with “exercise.”  Haven’t all of us, as a society, learned by now, that avoiding talking about something openly only leads to exclusions and hurt feelings?  I think we should all strive to be comfortable talking about, and accepting and supporting, anything/everything.