My experience with swimming is that the drag from the resistant medium outweighs the perceived &quot;lift&quot; from buoyancy.<p>I expect the disorientation, nausea, etc., would outweigh any short term muscle-feel effects.  For how weightlessness feels: <a href="http:&#x2F;&#x2F;science.howstuffworks.com&#x2F;weightlessness2.htm" rel="nofollow">http:&#x2F;&#x2F;science.howstuffworks.com&#x2F;weightlessness2.htm</a>