From lifting to running, when will I actually become a good runner?

I was a runner in high school and then a cyclist for a while, so my background is being lean and in endurance sports. During my late 20s and early 30s I spent a lot of time lifting. I didn't get as big as you (and probably not as strong, either), but I went from a lean 150 to an almost as lean 185 at 6'1".

Then in my mid 30s I got back into running. It took me a couple of years, thanks to many injuries, to get back to a 19 minute 5k. I probably lost about 20 pounds in that time. From there things kept getting better so long as I was healthy. Now I'm running 60 to 70 miles per week, I'm back at 150ish, and I'm significantly faster than I was in high school. And I'm still getting faster each year as a runner approaching the masters category.

Now, you worked on strength through your developmental years. I think that means it could take a long time. Don't let that bother you. If you like running, just keep running. It's been a year and a half that you've been working at it. Stay patient. And don't let yourself get injured.

Can you get to an 18 minute 5k and 7:30 pace on long runs? Maybe. We don't know what kind of talent you have. I do think a lot of healthy, fit guys can reach those benchmarks. But at the same time, I've seen plenty of people in my club with varying athletic backgrounds who put in lots of miles over a lot of years and they never break 20 in the 5k. People are just different.

You are right, it does take a lot of time to get aerobically fit and good at running. But I would argue it is similar in strength sports. With a good program you see some beginner gains. But if you're not a teenager going through puberty and lifting for all 9 of those years (9! That is a long time, imagine what you could do with 9 years of solid running), your gains in strength are going to be slow. And they also aren't going to last terribly long.

Learn to love the process. Take your time. Set intermediate goals. Don't chase goals that are too lofty in the short term. But don't shortchange yourself and limit your long term goals.

taking a week off of running has no negative impact on your actual fitness. you should not drop from 22 to 24 minutes unless you take several weeks off in a row with no other training.

so right away we know there's a mental component to your issue. that's something that you'll figure out the more experienced you are.

you mentioned injuries but didn't state any specifics. at 185 you're not a light runner so you should be careful with your shoe choices and the places you run. try to run on softer surfaces as much as possible.

you may never be a 17min 5k runner but it's impossible to know at this point. I'm a 15 min 5ker still trying to find out if I have the ability to be a 14min 5ker. you just have to try! you'll be just as happy getting to 19 min if you figure out that it is your peak ability level.

You are still pretty heavy for a runner, that is probably the biggest part of your injury problem.

Be patient and not expect any short term results from your running.

I would suggest that you run less miles per week and focus on your diet to shave off a couple of pounds.