First Marathon: what goal time should I aim for ?

Yes, breaking 2:50 is a realistic goal. I have very similar PRs and did similar mileage in my marathon buildup. Your 1km repeats don't say much, but the 35km long runs with 20km of work at sub-2:50 pace are very impressive. You've got the PRs to back it up, and you've run the mileage and done the workouts, so go for it.

my 2c wrote:

Yes, breaking 2:50 is a realistic goal. I have very similar PRs and did similar mileage in my marathon buildup. Your 1km repeats don't say much, but the 35km long runs with 20km of work at sub-2:50 pace are very impressive. You've got the PRs to back it up, and you've run the mileage and done the workouts, so go for it.

Thanks, I think it's worth a try...just didn't want to be over ambitious and die hard for the first try of marathon.

yeah, i suppose the 1km intervals are more 5km/10km training programs but just kept one speed session a week throughout my training

How many long runs over 20 miles in the past 4 months?

loki wrote:

How many long runs over 20 miles in the past 4 months?

They have all been in the last 5 weeks....1 each of those weeks that were 20 miles. Before that my long run was ~15 miles

I'm doing my first (London) in two weeks too.

5k -17:53 (16 weeks ago)

10k - 37:25 (8 weeks ago)

Half - 1:23:07 (5 weeks ago)

I've peaked at 87km, so way less mileage than you.

Will be interesting to see where we both end up :)

The marathon begins at 20 miles. I have run over 50 of these in the past 36 years, and all I can tell you is 6:30 pace is no joke to hold for just under a 3 hour time period. First time marathon should be conservative and negative split. It will feel great for 18 miles and then your training will kick in or fail you. I had to run a lot of easy 24-28 mile runs before I raced well over the entire distance. I also ran 3 full marathons at 7:00 pace with friends as training runs-back when entry fees were $20. This taught me to be conservative for the first 16 miles with the last 10 miles all in. If you cook it to early the marathon is a death march! Remember 16 miles of pace 10 miles of race. My test was 2 hrs easy running 8:30 pace then 10 miles at 6:00 pace. The last 10 miles are at a conservative goal pace in this workout. Remember also early on in the marathon if you are even 10-12 seconds to fast it will come back to bite you over the last 60 min. I would shoot for 2:56-58 (6:45 pace) for 16 miles and then go after 6:30-15 pace or faster if you can for the last 10 miles. The first marathon will never be your fastest, but it is so invigorating to run it coming home like a mad man than limping home a blown unit. Plus the recovery time is cut in half if you don't bonk.

I think 2:50 is a safe goal for you to go after.

Your PRs are totally in line with 2:50, but with the right training. If your run is more than 3 weeks out I’d suggest doing a 20-22 miler with a few 8:00 miles and then 3x4mi or 4x4mi at MP with a mile recovery at 7:00. If you fade during that run, you could back off a few ~5 seconds per mile from your goal and hope you are surprised at the end and can negative split.

Thanks for the advice. I tend to race conservatively (negative split often) so would likely do something similar

I hope you have a great Marathon. I'm just an old fart trying to help.

Well, I didn’t do 2:50..finished with 2:52:45 in the Vancouver Marathon. Still pretty happy as felt solid for most of it. Definitely underestimated the hills on the course as they took a toll. I found the first 30km were always going up or down with minimal flat sections but couldn’t make up the time lost on the uphills

Wow, OP delivers! Great work on a strong first result.