As a follow up from the previous discussion on negative vs positive splitting in marathons, I looked over some more real world data from the Chicago marathon frorm yesterday. It appears that in general, most sub 3 guys are fading by 2-5 minute in the second half. VERY VERY few are negative splitting.
The real world data would indicate that a strategy of taking the first half out 2-5 min quicker than your second half might make reasonable sense (based purely on the fact that this is what the majority of so called competitive runners are doing).
Here is a sample set from the men’s 35-39, places 50-75 who were in the 2:51 to 2:55 range. I took this set given that many likely have several years of running under their belts, so their execution is likely well tuned, compared to less experienced ruuners:
Click on any of the runners and see how they faded. You can also move up to the 25-50th place or 1-25th place and you’ll see everyone fading a bit.
Even the top 5 women ALL positive split.
If negative splitting is the way, to go, how come all these exceptional runners are positive splitting?
I am increasingly convinced that a strategy of actually trying to negative split is totally unrealistic unless you dog the first half and leave time on the table. Granted, running the first half 5-10 min faster than your planned second half is not what the top folks are doing, but 2-5 minutes is reasonable even at the front end of the pack.
just to play devil’s advocate, how do you that it was part of their strategy to run positive splits? maybe they all get caught up in the head games of jockeying for position early on. just a thought.
I agree that it is not their strategy, but eveyone seems to have this same 2-5 min positive split outcome even though they plan to even or negative split. Either we as a human species are stupid and cannot execute, or marathon runners in general typically slow down, so we should plan for it in our own race strategies :-). Seems like 2-5 min is a reasonable plan.
I negative split the marathon yesterday, and though I wasn’t as fast as the people you looked at, there is no way I could have run my splits reversed.
1:34/1:32
It’s a whole different game when you are racing for a place, and racing against yourself. Unless you are extremely fit, and hugely confident in your fitness, negative splitting when you want to win the race is risky. If you are just looking to beat a previous years self, I think it’s definately the way to go.
A marathon is a footrace. The strategy to win or place highly in a footrace is not always the same strategy as will produce the fastest time.
You keep saying that the fastest strategy is to positive split. Many of us disagree. However, I will readily agree that the best strategy in a race might be to positive split, depending on circumstances.
Hello, Sorry i still don’t agree with you. I think encouraging people to go out fast and then slow could result in many many people turning their positive split by 5 minutes stategy into a positive split by half and hour stategy. Most people who positive split a marathon intended to run even and miscalculated a bit. now your encouraging those same people to miscalculate a lot.
The fastest distance races are virtually all even or negative split.
I think that going out “easier” with the intention to -ve split will produce a result with a slight positive split for most people. You have to really know yourself to be able to truly -ve split a marathon, as it would take much practice in training AND a lot of miles under your legs.
That being said Dev, if people go out with the intention of +ve splitting I think for over 90% of the participants you would have mass carnage on the roadside for the last 6 miles.
I never said to hammer. Just take it out aerobically, but don’t dog it to the point of leaving time on the table. I don’t think any of these guys that I referred to in this post were dogging it. They took it out “conservative, yet quickly” to go 2:50 to 2:55. Why do you guys assume that if someone is going quicker in the first half that they will totally blow up?
Let’s say for someone on the brink of going sub 2:50, 3:00 or 3:10, it would be more realistic to go 1:23, 1:28 and 1:33 respectively in the first half, knowing that they now only need to go 1:27, 1:32, and 1:35 respectively in the second, vs going 1:25, 1:30 and 1:35 and hoping to hell that they have the legs (ie wooden quads), nutrition, miles and ability to not cramp to pull off the same split in the second half. I’d argue the even split strategy is more often going to result in missing the goal time since in the second half there are less factor in your control than in the first half.
I’d generally agree with a lot of people here. To even split, slightly negative split, or positive split a marathon, you really need to have a lot of base and a lot of really good understanding of your body and of the course.
For the masses, positive splitting is the reality, but I would wager that if polled, you would find that most intended an even or slightly negative split. Recognizing the amount of fall off could be huge, but most runners don’t know their bodies well enough. Even in the sample set shown (the first 75 runners), I would say that most followed the ‘conventional wisdom’ and tried to negative or even split.
Suggesting that most people try going a little positive is inviting them to go a lot positive.
I was looking this over as well. I think the contenders are running at the mercy of the eventual winner. The 1/2 M for the men was like 1:03:20 and when the stronger guys pull away, it’s lights out.
I don’t think the top guys have any choice but to run with the leaders if they want to win or get in the top 10.
PS - we had one D3 athlete neg split, 1:35/1:32 - and soon enough he’ll go under 3:00 using the same strategy.
My wife ran Chicago yesterday and her strategy was to negative split. Her plan was to take it out very easy for the first 5K as a warmup, then maintain a steady pace for the rest of the race.
She glanced at her watch but did not obsess over each mile split but instead went more or less by RPE. At the end of the race she felt like she hit each mile at her target pace.
Actual Results:
First 10K: 47 minutes
First Half-Marathon: 1:40
Second Half-Marathon: 1:49
Overall: 3:29
Basically, even though she planned to negative split and tried to negative split, she positive splitted significantly. If I had advised her to count on a positive split I think she would have gone out even faster and would have crashed and burned.
I think there is a lot to be said by racing by perceived exertion as opposed to getting hung up in the splits. I ran the race beside her and saw that by not obsessing over the numbers she could have a great experience and post some fast times. . . Her half marathon PR was 1:43, so she set a half marathon PR in the first half of the marathon and ran the whole thing very close to her half marathon pace.
She set her target marathon pace based on her pace during some longer tempo workouts as well as through some targeted track workouts. She never looked at a HRM and barely looked at splits, except for a few workouts when she ran at her marathon pace based on her RPE then measured the splits to see how fast she was going.
Her approach was totally opposite from mine, but by taking science out of it and putting more heart and feeling into it she had a great experience and posted a respectable time for her first marathon.
I think that going out “easier” with the intention to -ve split will produce a result with a slight positive split for most people.
if people go out with the intention of +ve splitting I think for over 90% of the participants you would have mass carnage on the roadside for the last 6 miles.
And there you have it. Aiming for a slight negative will usually produce a slight positive. Aiming for a significant positive is asking for catastrophe. Small positive splits are fine but you get to those only by trying for a small negative or even paced split.
I’ll repeat what I said on the last two or three threads that you posted on the subject. If all you are saying is that people tend to fade a little (2 to 5 minutes) over the second half of the marathon, despite maintaining a comfortable pace for the first half and running with increased effort over the last half and especially the last 10 KM, then I agree with you. If you are saying that running hard over the first half and then crashing over the last 10 KM is the best plan for optimal results, then I think you are wrong and I think these numbers confirm that. Slowing down a couple minutes over the second half is more or less evenly splitting the race. Head wind or not over the last couple miles, I also think that most of these finishers, if polled, would tell you that they ran fairly easily through the first half and picked up the effort, although slowing down slightly, over the last half.
I’m not saying hammer the first half. I’m saying that you can expect to slow down a bit the second half, so plan for it. I you run 1:30 the first half it is unrealistic to expect to run sub 3. You have to be able to run 1:28 fairly comfortably to hope to break sub 3. Just look at all the dudes who were just under 3 at Chicago and the bulk actually ran the first half in the 1:27 to 1:29 range, not 1:30 on the nose.
And I do feel that this whole views about, “telling people to slightly postive split, is inviting disaster” is totally patronzing.
Its not about telling people to run the first half any faster than aerobically feasible. Its actually telling them that you can expect to run the SECOND half slightly slower, so factor in a slight slowdown into your expectations on race day. If you plan to “even or negative split”, and assume that you are in the 1% that will, then most of the time, you will be dissappointed with your outcome, cause you’ll be part of the mass of people that positive split.
You are generally a smart guy in my book, but you are digging one of the kind of holes I usually do with this positive split stuff. A fade of 3-5 minutes is not like your plan of a ten minute drop. It is very hard to know your pace well enough to get a negative split right, because as we all know the first ahlf of a properly paced marathon will be ridiculously easy. My best paced (out of three marathons) was a 3:00:48, with basically a balls on 1:29 flat first half. The second half of the race had a lot of hills, so I call it pretty much dead even. I let up a little intentionally in the second half, to avoid a crash and only was only really hurtin the last mile or so, because I tried to get back to sub 3:00 in the last three miles after I knew I wasn’t going to hit the wall.
I went out at 1:25 at Boston this year and ended up in 2:58:50. Now a negative split at Boston is almost impossible and it got hot and I had to visit the port o john for a number 2 after heartbreak, so this fade was circumstantial. I was most certainly in 2:50-2:52 shape based on a 1:16 half four weeks out. So going for an even split probably saved me from a total melt down when things went wrong in the second half and I only lost 8 or 9 minutes, which isn’t all that bad.
I ran a half this weekend, not too hard in 1:17:21 (Zofingen workout, I did a two hour bike later in the day) and again negative split and felt strong at the end (I had to pick it up just a bit to ensure I stayed on the podium). This is not the best example, as I was not trying to run my fastest time, just get in a good workout and place well, without killing myself (I am a little bit sore today, maybe I did run pretty hard). I am a firm believer in negative splits, but I am probably in a small minority of people with the discipline to do it.
Your previous thread advocated a 10min positive split as the optimum strategy. We jumped all over that proposition, saying instead (for example in my post):
“The goal is even pace, on a great day a negative split may be possible, on a good day the positive split can be managed to be non-catastrophic.”
That’s exactly what these runners did. No-one plans to run a 3hr marathon at 1:30/1:30, that would be woefully overoptimistic. Usually the plan is for something like a 2:56, so 1:28 and hang on. That clearly works, as these results show. 1:20 and die is still not appealing or optimal, IMO.
Fair enough triyoda, but I have conceded to you guys that something like 1:25-1:34 is not the wisest strategy (even on a course like Boston which was part of the basis of the earlier discussion), but 2-5 min is reality in almost all marathons. I am a firm believer in negative splitting at distances shorter than marathon including your half marathon example. At marathon, all the evidence points to slowing down a bit. There are just too many factors that you cannot control as one gets later into the day, to deny that a slowdown is more than imminent no matter how well trained you are.
You point to your negative split as being “circumstantial”, despite a 1:16 half a few weeks out. What I am trying to tell you guys, is that pretty well everyone will have some kind of a “circumstance” in the second half of the marathon. Pick your excuse from the following list:
wooden quads
hamstring and calf cramps
heat
headwind
sunburn
aid stations ran out of gels
stomach cramps
dehydration
hyponatremia
All of the above
none of the above
Usually some of the above happen in the second half. Usually none of the above happen in the first half.
Life is to short.