Guess my 5k time from 12 x 400 workout - (probably 19 to 20 minute range)

19 might be generous. Some where between 19:30 and 21:00 imo

18.30

pgmt17 wrote:

12 x 400 with 1 minute rest

(86,86,83,85,85,86,88,87,87,86,88,81)

OP: I do not want to single you out. Often on LetsRun runners post 400m repeats and ask other runners to predict 5K/5000m. Not my high school XC coaches nor my college XC coach ever asked me to do 400m repeats during XC season. Please do (6 or 7) x 800m at 3000m race pace or (5 or 6) x 1200m at 5000m race pace. The reason why 400m repeats are not accurately predictive for races past one mile: 200/400m athletes can do these repeats with 5K runners but cannot necessarily race 5K as fast as a road warrior. Tell me your pace for a moderately hard ten mile run and I will tell you how fast you will race 5K.

Thanks, Ironside, this summer I ran a few 10 milers in the 1:12 to 1:14 range.

18:45 to 19:15

And I haven't run 800s recently, but a few months ago I did 6 x 800 averaging 2:58 or so.

Based on the 800s, 19:32

When I did my PR of 18:45 a couple of ago, I was able to do 20x400 between 75sec and 80sec (of course, I was completely exhausted at the end). So considering your 400s, I would assume something between 19:30 and 20:00. Of course, everybody is different, and maybe you have super endurance you can do better than 19:00. Btw, I am much better at endurance than speed (for example, I have 3:01 marathon PR but only a 39:04 10K)

Thanks for your input everyone! I haven't raced 5k in a while but I have one coming up, I think I'll aim for between 19:30 and 19:40, and that way I'll be pleasantly surprised if I end up running faster.

In terms of 5k strategy, I know everyone's different, but in general, is it wise to run the first kilometer or two below your goal pace, knowing that you might slow down the last km or so?

Or is it better to stick to your goal pace right from the beginning and run the last km faster if you still feel you have something left in the tank?

As mentioned 400s aren't a very good 5k predictor but for what it's worth I did the same workout with similar splits (in the rain though so that may have slowed me down some) 4 weeks ago and ran 18:1x in a road 5k on Sunday.

Depends on how they felt. I like 12x400 with 60s walk/jog as a light workout to hone in on race pace. Beyond that, as others have said, they shouldn't be part of your "bread and butter" 5k workouts. Last I did this, ran consistent 89-90 followed by 18:43 the following weekend. They felt insanely smooth and easily could have done more (but that wasn't the purpose of the day).

So if your reps were controlled and relatively easy then you may be looking at low 18s. But if the wheels were coming off then it could be upwards of high 19s.

ironside wrote:

pgmt17 wrote:

12 x 400 with 1 minute rest

(86,86,83,85,85,86,88,87,87,86,88,81)

OP: I do not want to single you out. Often on LetsRun runners post 400m repeats and ask other runners to predict 5K/5000m. Not my high school XC coaches nor my college XC coach ever asked me to do 400m repeats during XC season. Please do (6 or 7) x 800m at 3000m race pace or (5 or 6) x 1200m at 5000m race pace. The reason why 400m repeats are not accurately predictive for races past one mile: 200/400m athletes can do these repeats with 5K runners but cannot necessarily race 5K as fast as a road warrior. Tell me your pace for a moderately hard ten mile run and I will tell you how fast you will race 5K.

This^

400s are no good objective measure at all for anything 3k and up. You might be able to run 87''/lap all day or you might be lucky to break 20 for the 5k. Very good 5k workouts in my opinion are 5 - 6 x 1000 or 1200. Like 5 x 1k with 2 - 3' rest at pace, the last one pushing it a bit. And don't forget those tempo runs.

Since I get annoyed with people who want time predictions but don't post follow ups...

I ended up running 19:24, someone a lot faster offered to pace me, it was the first run in a long time where I didn't even look at my watch!