Very interesting Freediver.
So, do you use the device during just breathing exercises, or, do you also use it while doing cardio work?
And would this be the same as hypoxic drills, where you try to force your body to make due with less O2? I'd read that hypoxic drills are supposed to increase the amount of hemoglobin in your blood, which as I understand it, it's the hemoglobin in blood that actually carries the oxygen.
Ever tried swimming with that thing in your mouth? I'm afraid I'd forget, and try to breathe through it like a snorkel (face down). :11: