Review on 🏋️ Vikingstrength Adjustable Resistance Workout Mask with High Altitude Elevation for Running, Biking, MMA Endurance and Air Resistance Training by Doug Nelson

I have selected a couple of training masks to compare and of the three I have this is my least favorite although it looks smooth. The problem I have is that the valves are too close to the mouth. There were times when my breathing quickened due to the intense workout and I naturally needed more air as I inhaled deeper with the mask touching my lips. With another training mask I don't have this problem no matter how hard I breathe. Even if I don't take a deep breath, it's still too close to be comfortable. It also tends to slip a lot if you have too many sweaters. Does it do what you want it to regulate the oxygen flow, yes absolutely. Is it the best design, no, not really.