The Valsalva maneuver involves inhaling low and can be performed through pursed lips or the nose, but not an open mouth, to create intra-abdominal pressure for stability.

“so it's like so the Val Sala maneuver one uh Russian coach called it it's it's an ex it's a it's an exhalation that didn't happen Okay because people don't know hold their breath properly they just and then eyes are bulging out well there's no stability right here so first of all you got to inhale low and how do you do that if you watch top lifters how they do that they will do it through purse lips you can also do it through the nose but you cannot do it through big wide open mouth”