Rowing machines come in several models, but they can also be classified by more criteria. For instance, you might need to decide between folding and fixed machines. Each type has both pros and cons. More and more people choose the folding model because it occupies less space. Also, storing it away should never be a problem. You can put it behind the wardrobe or in a tight place down in the basement. Rowing machines can be used outdoors too, in your backyard. For indoor uses, most people would rather go with the folding unit. Check rowflow.net and read a few reviews too.