Some incredible runners here on getbig. Someone suggested running 26 seven minute miles is just okay running. Amazing. Some cardio animals here.
If you are a bodybuilder who devotes most of his time to lifting then one 8 minute mile is fairly good for cardio efficiency. If you dedicate some time to running a 7 minute mile it will put you ahead of the majority of joggers. If you can run a 6 minute mile there are very few that keep up with you except dedicated runners. When you get down to a 5 minute mile that's where you get to a speed where it's hard to find anyone but a few guys on a high school track team that could keep up with you.
I was a sprinter in high school but I could string together a couple of 5 something miles. At age 47 I could hit one 6 minute mile while mainly lifting weights. Now as I approach 55 a 7 minute mile feels like I am flying but I still think maybe with delusion that I can break 6 minutes if I put the work in.