Breathing the Valsalva maneuver

[Arnoo]

So here i am reading my book about weightlifting (Starting Strenth: Basic Barbell Training by Mark rippetoe & Lon Kilgore) and i stumble upon the section breathing under the squat chapter. Now what i thoughed from reading internet etc etc is that you are supposed to inhale on the way down exhale on the way up. However the book says inmagine if you would have to push a car of an intersection very quick. Then you'd put your shoulder against the doorframe take a deep breath and push and while inmagining that, i thoughed damn he's right. Then he explains you'r supposed to do the same while doing heavy reps its called the Valsalva maneuver. Aka take a deep breath and start the movement and trewout the movement slowly release presure either by vocalizing (grunting for example) or just exhaling slowly.
So basicly if this is true then i've been doing it all wrong (also explains why often my back feels to "sore" after a workout out from not counter pressuring the anterior side of my spine by holding my breath). What i wanted to know is this true and dous this apply to all lifts not just pushing motions like the squat and bechpress but also pulling motions like the deadlift.

[Dragon Brush]

The Valsalva Manuever has a little tendency to create a massive build-up of pressure in the chest cavity, and can pinch off some main arteries temporarily, so anyone concerned with their blood pressure should try to exhale properly to minimize this.

[Dillon]

It's a balance of spiking your bloodpressure vs. stabilizing your trunk.

[Arnoo]

So it is the way to go and its just trying out in the start to get a feel for it.