I hadn't really thought about "reaching and maintaining a certain level of conditioning" but that's probably true. I guess I reached that a long time ago. I've

I hadn't really thought about "reaching and maintaining a certain level of conditioning" but that's probably true. I guess I reached that a long time ago. I've been on a 3-mile plateau for decades now with no desire to run any farther. I definitely don't feel like just running is enough, so alternating cardio and strength works better for me. YMMV.