Bas Rutten has a serious line of products that can help any athlete or aspiring fighter. His O2 Trainer, he claims has ridden him of his asthma. Others have claimed the product gave them the same results. So what is an O2 Trainer anyways?
It's essentially an altitude mask or an apparatus that hinders the amount of air you breathe in. It forces your lungs to optimize the amount of oxygen they receive. Altitude masks simulate climbing a mountain at high altitudes with low levels of oxygen. Bas's O2 Trainer does the same thing, just a little differently.
The entire package comes with different fittings for different O2 Trainer settings. It comes with a 30 day love it or your money back guarantee. Bas really stands by his products. This one is easy to use, just breathe through it while your working out or as Bas states, you can simply do breathing exercises with it.
Out of it's 300+ reviews on Amazon, it's almost a 5 star product. Most customers ranting and raving over how well it has improved their breathing or cardio. The only negative review I found said the product changed their voice but, I feel like that's a little farfetched. This product really seems to work!