Behold, the respirocyte.
A respirocyte is basically an artificial red blood cell a micron in diameter, a spherical nanorobot consisting of a pressure tank that can be filled with oxygen and carbon dioxide and emulate the functions of a natural haemoglobin containing red blood cell, only with approximately 200 times the efficiency. It only takes someone with a vague background knowledge of biology to imagine what this can do. With such efficient oxygen delivery to tissues, theoretically one could hold one's breath under water for hours, or run at top speed for incredible distances without becoming breathless.
One of the most awesome things to look forward to with this sort of technology is, of course, the wide range of excuses, dodges, lies, and bald-faced denials that pro cyclists will come up with when they're caught using it.
200 times the efficiency?! Holy Hell, I'll be able to smoke and win the TDF... underwater!