I used Oxydrene before I went scuba diving and it's such a powerful oxygenator that I didn't even need the air tank! Next thing I new I had swam around the tip of South America, back up to Panama where I actually bench pressed the Panama Canal! No joke! Then I swam back home and made it just in time for dinner! Afterward I exercized on the Gazelle for a couple of hours cause when you're in great shape like me (thanks to Oxydrene!) that's all you need. Fo shizzle!