The Rowing machine is a very good means of developing sinew strength and endurance. It's a whole body exercise and I used to do it a lot. In my view, do it as a supplement to Outdoor Running and not a substitute for the same.
Originally Posted by Sarzis
Doing both will allow for major gains in improvement for your underlying Conditioning - Cardio-fitness - and Strength-work.
Remember, it's a balance. If you go bonkers on the Rowing machine, it will bite back. Be sensible, the same for your Running.