All the big organisms on the planet need a healthy supply or oxygen, yet there are a myriad organisms at the other end of the scale that either ignore oxygen or are actively averse to it. How come none of our large scale creatures have come from this anaerobic stock? [more inside]
posted by twine42 on Mar 27, 2009 - 16 answers

I want a high intensity, low-impact workout that I can do every single day, indoors, with minimal space requirements. Jumping rope in my apartment lobby is absolutely perfect except that my feet and knees can't do it daily. [more inside]
posted by zeek321 on Jan 30, 2008 - 35 answers