I would change the opening post slightly to say that fix gear riding does all that but the upper body/overall conditioning side of it better. Especially if you take the fix gears into hills. The more I ride fixed and the more hills I ride fixed, the better strength I have, the easier tool use and yard work are, and the bigger the bounce in my step (except after rides!) The more fun weight lifting is. A 15 mile ride from my house to the Portland hills in my backyard is a whole body workout - even when I bring the extra cogs and change them. (There are always some quick little rises and descents that aren't worth stopping for so I may be doing them in a full-body weight lift 42-12. Or spinning down them at an insane RPM 42-24. This is as an old man. When I was young, it was all 42-17.)