Is not a benefit of improved cardio-respiratory fitness A. Faster post-exercise recovery time. B. Arteries grow smaller. C. Lungs expand more easily. D. Diaphragm grows stronger.?

B. Arteries grow smaller is not a benefit of improved cardio-respiratory fitness. In fact, improved cardio-respiratory fitness typically leads to healthier arteries that can maintain or increase their diameter, promoting better blood flow. The other options—faster post-exercise recovery, easier lung expansion, and a stronger diaphragm—are all positive outcomes associated with enhanced cardio-respiratory fitness.