I’d like to know what’s the science behind the fact that Win Hof breathing technique, as well as Tummo breathing I suppose, can double the amount of repetitions one can do on one exercise. I’ve tried it out with push-ups and pull-ups. I believe it might be related to the amount of CO2 in blood, it must be greater than usual and more oxygen can be delivered to the muscles involved, but I’m not sure. Can you clarify this, please?