Low Mileage wrote:
I recently ran a half-marathon in 1:25 (37 years old) running only 3 days per week, averaging about 24 miles per week. Two of those three days were jogging commutes to work with a backpack on, and the third run on the weekend was a tempo run or a long run. How much more do you think I would need to do to run a sub 3-hour marathon? I have never run a marathon before.
This was basically me a year and a half back. I was running about the same without a specific tempo or long run, and I ran 1:24 (nice negative split). That being said, my every-other-day runs were all steady and probably higher quality than the jogging commutes.
My long saga in short, I think you can hit a sub-3 if you get to 3 months of 5/6 runs a week averaging 45 mpw with one workout, and one long run. I ran under 2:57 with that. You seem to of similar raw talent.