Where to buy one of those Sport Masks that people wear in the gym? and what are these sport masks used for?
I did a bit of research about this kind of sports mask and their benefits:
“Function: Increase lung’s capability, strengthening the inspiratory and expiratory muscles, enhance the function of the heart, enhance physical endurance as well as oxygen absorption efficiency”
There some more information on Dream Health Shop. Click on the link below to see the sports mask product and its usage description.