Was searching youtube and found this product which has mediocre validity behind the way its meant to work.
"increases your lung capacity, improves your oxygen intake, and improves your endurance by exercising all the muscles required for breathing."
From years of swimming i know that putting my lungs under regular strain and oxygen deprival that i can hence hold my breath longer. Didn't consider the strength benefits from this tho allowing more oxygen to muscles? Idk
What do you guy think?
Thread: Wierd ass contraption