To me, the increased volume alone suggests there should be enough room for a 9 minute improvement. With the other variables in place, I would think you’d even have some cushion.
Sometimes, things fall into place much more quickly than we expect. About a month ago, I was concerned about where I stood. Saturday, I ran the exact same time as I ran in the same race three years ago when I was in the best shape of my life and this year’s course was more difficult than the course I ran three years ago. I also feel like I have more room for improvement over the next few weeks than I did three years ago because of how I felt during the race. In a month’s time, I went from concerned that I wouldn’t get things put together and looking at some conservative goals to feeling like I’ll be in the best shape of my life within weeks and looking at the most aggressive goals that I set for myself at the beginning of the summer. Things just fell into place as I worked my way through the planned training and kept faith in the plan. I’m sure you will find the same to be true in the coming month.