Saturday, July 4, 2009

Run Pacing

I recently came across some interesting data on pacing of world records in endurance running events on the track. It indicates that nearly all of the record-breaking times in the last 40 years or so have been run with negative splits. That means the second half of the race was run faster than the first half. This, of course, has to do with the pacing strategy I write about so often—holding down perceived effort early in the race rather than starting out of control and then limping to the finish.

Here is the basic data I refer to...

Between 1967 and 1998 the men’s world record for the mile was broken 10 times. Of those 7 were negatively split, but just barely. The average first half time for all 10 was 50.3% of the finishing time (+/- 0.53%). In other words, on average, the first halves were run more slowly than the second halves of the race.

Same thing here. From 1966 to 2004 the men’s 5000-meter world record was bettered 13 times. Twelve of those were negative splits. The average first half was 50.3% of the finishing time (+/- 0.71%).

And finally, the men’s 10,000-meter world record was broken 14 times between 1977 and 2005. Of these 11 were negative splits with the first half being run in 50.2% on average of the finishing time (+/- 0.22%).

The bottom line here is, once again, that if you want to run a fast race it appears to be beneficial if you start conservatively and pace yourself so that the second half is run slightly faster than the first half. Of course, this assumes that the course is flat and wind is not an issue. That is seldom the case, So the better way to think about this, given that terrain and weather may well be issues in pacing, is to focus on perceived exertion. Run at a lower effort than what you feel like you could do in the first several minutes and you greatly improve your chances of a negatively split race.

I tell the people I coach that when a running race starts, if they aren’t being passed by nearly everyone who started around them then they, too, are going too fast. I tell them to be patient and have confidence that they can finish stronger—and race faster—if they merely hold back a bit at the gun. Nearly all of those who passed them will “come back” later in the race. And it is very stimulating when this happens. Passing others late in the race keeps you focused and racing aggressively.

The problem is that most runners can not control their emotions at the start. If the person next to them is going too fast at the start then it is assumed that is the proper pace. You’ll never realize your potential as a runner until you learn how to develop and follow a pacing strategy. This requires both mental control and physical practice.


At July 4, 2009 6:59 AM , Blogger Matthew Ozvat said...

Thanks Joe for this thinking. I agree completely with this and have always felt I try to perform negative splits on purpose for a number of reasons.

1) I find it rewarding to "reel" in those that passed you, providing some mini-goals.

2) It allows me to get in a groove the first half of the longer event (physically and mentally).

3) I can assess how my body feels that day. For example, I can assess the overall amount of energy I have and determine how to spend it and finish the event respectfully.

At July 4, 2009 12:47 PM , Blogger junatik said...


Thanks for the analysis. I was wondering if this also applies to a mountain bike race where generally the first part of the race is open and the remaining is on single track where it's harder to pass? Thanks.

At July 4, 2009 1:59 PM , Blogger Joe Friel said...

junatik--No, not when it narrows down soon after starting. But once into position on single track you can back off.

At July 6, 2009 10:38 AM , Blogger Rakicy said...

A while back Runner's World had an article about starting a 5k 3-6% faster than a person normally would and that person would actually end up with a better time. Additionally, those behind you that raced at the pace the same person normally races at would not be able to catch up.

Do you have any thoughts on the comparison of your post and this article, as it would seem in the RW article a person would be slowing down throughout as opposed to doing negative splits?

Thanks for your insight!

At July 6, 2009 11:10 AM , Blogger Joe Friel said...

Rakicy--Thanks for your comment. I haven't seen the RW article so don't know what data they are basing their claim on. I can only point to what the research and the results of top athletes seem to indicate about negative pacing benefits.

At July 6, 2009 12:08 PM , Blogger Geo said...

Very interesting, but it seems the numbers for the 5k and 10k are more intriguing. In the mile, the time to accelerate to race pace from a standing start easily explains a 0.3% difference. If estimated at 2-3 seconds and removed from the calculations it would suggest a pace for the first half of the mile which is faster than the second. Consider too that the extra muscular expenditure to accelerate gives a total energy output for the first half which is on paper larger than the second. (On paper = not factoring for heat buildup & possible efficiency degradation from lactic acid, etc.)

At July 14, 2009 1:21 PM , Blogger BobC said...

When I was doing 10Ks 20 years ago, I would *always* jackrabbit from the start. I couldn't help myself. After running ended for me, I joined a cycling club, and I would *always* leap out at the start of every timed event.

I must have had the mistaken notion that quickly jumping to the front would so demoralize my foes that they would fall to the sidelines and let me win. Never happened that way, of course.

Less than a year ago I started triathlon and finally became a swimmer. Fortunately, I was coached to start slow, "find my stroke", then ramp up to "cruising speed", always saving a the top-end for getting through crowds and making a fast exit.

The reason this worked for me seems to be due to the simple fact that I don't see as much of the other racers while swimming, since my face is in the water most of the time. And this lets me focus more on my form and power.

I've recently applied the same mental state to my biking and running, and both immediately improved.

I now know I need to ignore the rest of the field until my own engine has come up to speed and is running well. Only then I can take pleasure in weaving through the crowd in front of me.


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