I came across this quote and found it interesting:

"Going out 10 seconds too fast in the first 400 meters of a 5k race can lead to losing a few seconds in each 400 thereafter.  So, you might gain 10 seconds, but lose 30, for a net loss of 20 seconds"

He goes on to talk about how giving away 5 seconds in the first 400 meters would be a better choice, and I couldn't help but think of all the times in years past I had run 10, 20, 30 seconds or more too fast over the course of the first mile of a 5k, only to be completely gassed during the last mile.

This year, I have focused on not exceeding goal 5k pace (for the most part) until the last mile and have been able to negative split each event.

Some of that is mental, but could just running 10 seconds too fast for 400 meters have such a profound effect on energy stores and the ability to crank it up late in a 5k race?  Also, has anyone changed their 5k pacing/racing strategy and if so, what were the results?

Sure. I’m sure there’s some nice calculation out there where the statistical average slowdown is x seconds for every y seconds over z meters…zzzzzzzzzzz.

If you took that information, how on earth could you possibly put it to some sort of mechanical use? You’d have to somehow successfully guess/estimate what your optimal 5K finish time is for that day. How would you go about that? You’d have to take into account how you feel, the course, the weather, ad infinitum…and there you are, on the line “Ok, man, take the first 400m in 2:03 or ELSE!!!!”. And you’d have to somehow execute that. Good luck.

The “secret” to 5k pacing is to run a million 5ks until you “get it right”, until you learn what 5k EFFORT is. Once you know what 5k effort is, you don’t have to look at your watch, or do some whackass calculations. You just have to run that effort.

Don’t know if that’s helpful or not. Just this fool’s opinion/experience.

 

The “secret” to 5k pacing is to run a million 5ks until you “get it right”, until you learn what 5k EFFORT is. Once you know what 5k effort is, you don’t have to look at your watch, or do some whackass calculations. You just have to run that effort.

 

I used to think I spent my energy almost perfectly during my last 5k. Recently, I've come to realize it was just a really big fluke.

The “secret” to 5k pacing is to run a million 5ks until you “get it right”, until you learn what 5k EFFORT is. Once you know what 5k effort is, you don’t have to look at your watch, or do some whackass calculations. You just have to run that effort.

I like that number!  My next will be my 15th.

I have spent a great deal of time during training of correlating effort to pace.  During an event, I find that I am often running at what I think I am (based on discomfort or lack thereof), but sometimes I am not.

I still have a long way to go but hey, it's a process.  I'm getting there.

Think back to Fuzzy's race report that was up recently.  He eased into his 5k like you would a marathon and, if I'm recalling correctly, ran pretty close to a PR.  If it works at longer distances, and it certainly did for me in my last marathon, why shouldn't it work in a 5k?

 

After the workout I just did today (3 miles descending, 5:58, 5:50, 5:38, with 1 lap recovery jogs btwn miles) I'm thinking I may try and employ that strategy the next time I race a 5k - who knows when that will be since I never race them.  The effort just feels so controlled that way, and it seems like I can get the last mile faster by building into it than what the first mile would have been had I gone out hard, if that makes sense.

Your splits are pretty close to my 5K splits in my race IIRC. The funny thing with my race was that I hadn't been specifically training for a 5K and was just using it as a little fitness check. I decided that if I felt "good" at mile one I would try and pick it up. In hindsight it produced a damn good result.

I don't race a lot of 5K's but this one went so well I think the approach makes sense. The key with easing into it is finding that fine line between too slow and leaving time on the course, and too fast causing a big fade at the end.

I also like Paulski's strategy. 5K's are hurty no matter what strategy you employ. At least they should be. I'm of the opinion that if you don't feel like throwing up/dry heaving at the end of a 5K you have left a little on the course. The 5K and maybe the 10K are races where I agree with LtH's pain cave description.

 Here's my 5k racing stragey:

 

Mile 1: Run really fucking fast

Mile 2: Starting to tire; run faster

Mile 3: Might vomit; run faster

Last 0.1: Lungs about to explode; sprint

 

Post-race: collapse

+1!

Haha, yup that sounds about right, worked for my PR that I got last Wednesday night!

Anyone who thinks the best way to run a 5K is to ease into it and run a lot faster as the race goes on needs to tell every world record holder that they've been doing it wrong.  In earlier generations, the typical kilometer splits showed a fast first kilometer followed by a very gradual slowing for the next three kilometers and a final kilometer that was the fastest of the race.  Since about 1980, world records have been set with very even splits with the final kilometer still the fastest although not by much.

Here's the Analysis

 I just think that most of the 5k reports I read on here describe people fading like crazy because they've gone out too hard. 

That was the impetus for this thread, that going only 10 seconds too fast for 400 meters, or 20 seconds too fast for the first half mile, could be responsible for that.

Drastic fades occur less often with experienced runners but still they do occur.