Originally Posted by downtube42

Science? There's the scientific method, which nobody here is following, and there's the current body of scientific knowledge, which is to say, the current theories that we know are mostly wrong but are the best we have at the moment. And of course those are debated because that's how it works.

Anything citing science and hawking pickle juice derivatives or any such for-profit product is not science, it's marketing.

AFAIK there are issues with the various theories for gravity, for example, but we use what we have because it's the best we have. That ain't sexy, unless you're using the uncertainty to hawk your anti-gravity ankle bracelets.

Lungs burn because they can't deliver as much oxygen as the body needs. Muscles burn because they didn't get as much blood flow as they need. Maybe some studies somewhere, funded by some national sports program, but I don't know you'll find them.

I'm going to go ride my bike now, and collect one subjective data point.