I have tried a few of these types of trainers that strengthen your lungs & like Bas Rutten’s O2 trainer the best. It utilizes the concept of progressive resistance much more effectively as you slowly work your way to stronger lungs & cardiovascular ability by selecting different & more challenging mouth pieces that fit easily onto the trainer.
Several years ago I had massive heart failure, as a life long mountain sport athlete I was devastated. Forget climbing mountains climbing up my spiral staircase with groceries made me feel like I was dying. My challenge now is to get what is left of my heart to be stronger than it ever was. This is when I got my O2 trainer. I started by using it pool running everyday then on the treadmill & lifecycle exercise bike. It didn’t work overnight, I really had to be dedicated, like any exercise tool. The real test was using it in intervals while hiking Mount Monadnock this summer.
It has been less than a year now & I climbed 9182 feet on Mount Thielsen in Oregon along with white water river boarding & I felt great. I just ran my first 10K in Iceland & am training for The Marine Corp Marathon in DC. Thanks to my wife’s support & this O2 trainer my hearts ejection fraction, a measurement of how much oxygen leaves the heart, is up from a mere 15 when I was told I had 5 years to live by my cardiologist to 45, still under normal but what my doctors said was record time.