I'm considering doing a 50K one month before Boston. Thoughts? I would treat it as an easy long run before the taper. Emphasis on easy. It would be my longest run ever, but really, it's just like 4 miles longer than a marathon. I think they have good swag is one reason. Another: I need to fine-tune my hydration. On training runs, I never worry about stopping to pee (and I run with a Camelbak on many long runs, esp. in the summer) But I had to stop to pee in my last marathon and cursed the time impact. In this organized race, there'd appear to be plenty of aid. Another: Don't see that I'll be getting much pre-Boston racing in. Another: I could say I did it.

Math was never my strong point - but I've verified, this is a 50K, not a 50 miler.

I did a marathon 7 weeks after a 50k, also ran a PR. However, 3 weeks after the 50k I failed to run a 5k PR (I did have a 1 second season best time for the 5k though.)

I've run a 5K the day after a marathon, and a marathon the day after a 5K. On neither occasion was the second race exceptionally good for me. Go figure.

I've done a 5k 3 days after a marathon the past couple of years. Those runs are just to get my name in the paper and because I sponsor the series (which runs over 19 weeks) and I rarely race during them anyway. In fact, there was a 5k 3 days after the 50k last September. It really wasn't a pleasant run and it was all I could do to keep a 9 year old girl from beating me.

I'm curious what everyone thinks about doing a 5K the week before a marathon. Gut instinct tells me not to since I haven't been doing much speedwork and it's my first marathon, but I just saw a local one advertised today and was considering it.

Sure, you could. But why? Personally, I would not risk the training I put in for the first marathon. What if you pull a hamstring HTFUing to the 5k finish line. There's a lot more 5Ks for you to run afterwards.

I can't believe I didn't even think of this. Thanks for the wisdom Mike.

No problem. My brain wasn't firing on all cylinders during my taper either. Use your marathon training to set some monster PRs after you finish and recover. My last two HM PRs came three weeks after my marathon and ultra.

The 5K I did the day before a marathon, I had done a couple dozen marathons already, it was not a marathon I had a need to do well at, I found out they were putting on a 5K within a block from my house, and they were running it on my birthday. I couldn't say no to a race through my neighborhood on my birthday. Of course, that's frequently a problem for me... I can't say no. :-)