Rowing is a lot closer to swimming than running, primarily because the load on your joints is dictated by the output of your muscles, whereas in running the loa

Rowing is a lot closer to swimming than running, primarily because the load on your joints is dictated by the output of your muscles, whereas in running the load is primarily impacted by each of the small "falls back to Earth" you do with each step. That's not to say that improper rowing cannot cause injury, but the correct technique for rowing alleviates all of the injury-causing jolts to your joints that occur with each stride in running.