What DaveB said... I would add, though, that sweat impact can be minimized by simply placing a towel over the top tube. Won't catch everything, but enough to make it easy to clean up when you're done. I have the magnetic trainer - it's true it doesn't feel as real as fluid or riding, but beats nothing. I also do a full range of weight lifting - don't get the impression I'm talking about power lifting, etc..., simple stuff to build and maintain strength. Building cardio endurance for long climbs is important to me. About two years ago I discovered the best cardio work is easily at hand for anyone and does not require much space or expense - jump rope. It's also a good impact workout to help keep bones strong.