Is CIM the Vaporfly 4% of Marathons?

Your questions are inane and a logical leap from my previous statements. All I am saying that the majority of the significant hills are in the first half of the course, which is attacked with fresher legs and tighter pack running, so the slowing effect of those hills is somewhat negated. The 2nd half of the course is flatter with smaller rolling hills and has a very slight downhill. Overall, more downhill than uphill with most of it during the first half. How much that helps is debateable, but it certainly doesn't hurt to have those conditions in the 2nd half of a marathon rather than the Newton Hills or bridges over the East River and the hills of Central Park.

I'm not ignoring the weather, pack running, general racing environment, etc. All I am saying is that the course seems to have certain advantages over a flatter loop course that might help with a minute or two. I don't know why that is so hard for people to admit.

what's the rest of the story? wrote:

Milton Friedman wrote:

According to JK's rule of thumb, ~325 feet of elevation loss provides 58 seconds of assistance.

and what was JK's rule of thumb about the amount of elevation gain? Certainly JK was too smart to say that only the "net" change mattered. So what was his rule for the loss for the elevation gain of a course?

Of course hills slow you down -- nobody disagrees with that.

But it's absurd to run a net downhill, point-to-point course and call that your PR.

Say I ran a loop course (no elevation loss) with the same rolling hills as CIM, should I be allowed to subtract 58 seconds from my time and call that my PR? Because that's exactly what you're doing.

Nobody's calling Molly Huddle a 2:24 marathoner because she ran 2:26 at New York.

I don't know your profession but I don't think it is in the sciences.

Milton Friedman wrote:

what's the rest of the story? wrote:

and what was JK's rule of thumb about the amount of elevation gain? Certainly JK was too smart to say that only the "net" change mattered. So what was his rule for the loss for the elevation gain of a course?

Of course hills slow you down -- nobody disagrees with that.

But it's absurd to run a net downhill, point-to-point course and call that your PR.

Say I ran a loop course (no elevation loss) with the same rolling hills as CIM, should I be allowed to subtract 58 seconds from my time and call that my PR? Because that's exactly what you're doing.

Nobody's calling Molly Huddle a 2:24 marathoner because she ran 2:26 at New York.

No, that is not what we are doing., and it's not absurd at all. 'm not sure if you are really not understanding this,...

We are saying that the "net downhill" tells you nothing about the difficulty of the course. You need to know how much uphill and how much downhill is on the course. These two would be different difficulties:

1) zero uphill, 320 feet downhill (net downhill 320)

2) 700 uphill, 1020 downhill (net downhill 320)

#2 would be legit for a PR, because it is slower than a flat course.

#1 would be faster than a flat course, so would be kind of weak to call it a PR without noting the aid you received

No one under 2:10 wrote:

The fact that no one has broken 2:10 is not indicative of whether CIM is a fast course or not. Men US marathoning is just not competitive internationally (except Rupp).

I personally find the idea of a PR on a downhill (and potentially windy) point-to-point course disturbing. To me, it cannot count as a PR and indicating it as a PR may be a sign of low moral standards. Not as bad as doping, but already a red flag. Bigger than wearing than Vaporfly 4% (what I would personally not do).

To sum up, I think that downhill courses should be avoided by serious runners. Yes, even Boston.

There was no wind. It was 41 degrees. They ran many uphills as well. The net difference in the grade is not that big. They ran with their own legs. To sum up, you're jealous.

You're welcome to define a "legit PR" however you'd like, but many of us think it deserves an asterisk, because the course is not world record eligible. Ryan Hall has an asterisk next to his 2:04 at Boston, but it's still an impressive achievement.

Well, I am an amateur and I am going to call it a PR if I run it at CIM. I don’t think anybody cares about world record eligible courses, and I know it is slower than flat. And when I look at pro times from CIM, I will know that it is slower than a flat course (assuming no big tailwind).

As for the course itself, it’s quick with how it’s designed, especially the first half. You definitely get some time in the bank or spend less effort running the same pace. There’s a few punchey hills that make you work, for what it’s worth.

As for “how much faster”, it depends on what you compare it to. The weather and lack of wind is the main reason for the fast times in my opinion. It was damn near perfect conditions yesterday. Compare CIM to Berlin on a perfect day and I’d think the times would be similar. Compare it to NYC and obviously it’s much slower.

Also, don’t hate on the PR times from yesterday. Train and run the race if you are so convinced that it’s rocket fast.

I think he is too young to have a profession.

Vaporfly Asterisk wrote:

Sad to see no one has asked the obvious follow up question:-

If CIM is the Vaporfly of Marathons, then what's the overall gain running CIM wearing Vaporfly 4%??

I'd like to know this, too. I was practically blinded seeing all those Vaporflys amongst the leaders. Even some of the slower ones had them-haha!

LOL at the last statement. I've run CIM 6 times over the years and the bus driver has gotten lost 2 of those years! How hard can it be to get to the Start line? Must say that both times I had plenty of time before the start.

FWIW (nothing, really) I think CIM is about a minute to 2 minutes faster than a flat course run under similar weather conditions.

Sure, pile it on, boys! Give me some data!

My PR by about a minute and a half was at CIM. The first half was tough for me, but the last 10 miles were the best I’ve ever felt at a marathon. That said, it was 30 degrees at the start and high 40s at the end with no noticeable wind.

As a FL runner, I’m convinced I would have run faster on a flat course that day. I think Chicago is a faster course for a flat lander.

Amerikano wrote:

As for the course itself, it’s quick with how it’s designed, especially the first half. You definitely get some time in the bank or spend less effort running the same pace. There’s a few punchey hills that make you work, for what it’s worth.

As for “how much faster”, it depends on what you compare it to. The weather and lack of wind is the main reason for the fast times in my opinion. It was damn near perfect conditions yesterday. Compare CIM to Berlin on a perfect day and I’d think the times would be similar. Compare it to NYC and obviously it’s much slower.

Also, don’t hate on the PR times from yesterday. Train and run the race if you are so convinced that it’s rocket fast.

There is no way the first half puts time in the bank- are you kidding? The first half has almost all of the uphills. It runs about 30 sec slower than the second half (around 3:00 pace- I’m an old slow guy).

Did you really run it? Maybe you meant to say the opposite.

Yes I’ve run the course so I’m speaking from experience.

And dude, you get a 220 foot drop in the first half marathon. How much drop do you want? Just a simple look at a elevation chart and it looks like Bitcoins YTD price.

Give me a break. Are you suggesting the first half is up hill? It’s not why you be misrepresentin’

Look the fact that all theae people are having tortured argument on why it’s not really downhill or there’s no great effect from the net downhill kinda show there’s a huge benefit.

And to all those saying “well there are uphills too” miss the point. It’s a fast course.

I don't know if other people had similar experiences, but I ran in vaporflys yesterday and my quads were destroyed in the hills and I thought I was going to have to drop out around 18-19. Then as soon as I hit the flatness of the last 5 miles my legs felt fine. So I don't know how much vaporflys actually help on hills.

FWIW I ran Chicago in vaporflys 2 months ago and my legs felt amazing the whole race and I could definitely feel the (4%) difference from other racing flats.

4.5% wrote:

I don't know if other people had similar experiences, but I ran in vaporflys yesterday and my quads were destroyed in the hills and I thought I was going to have to drop out around 18-19. Then as soon as I hit the flatness of the last 5 miles my legs felt fine. So I don't know how much vaporflys actually help on hills.

FWIW I ran Chicago in vaporflys 2 months ago and my legs felt amazing the whole race and I could definitely feel the (4%) difference from other racing flats.

you seem very undertrained for any sort of hills. the last 5 miles aren't significantly different from miles 13-21, and there is basically one hill (a bridge) after mile 13.

I'll add my name to the HUGE list of people who have run CIM and think it's a fair course if there's no tailwind.

I'm from Sacramento and am very familiar with the course. I've run it in '15, '16, and '17, though only really raced it in 2016 when I ran 2:32, my current PR. I have run no other "fast" marathons other than Boston this year to compare times with.

My thoughts echo what some others who ran have said. The course is fast, but the weather in the last 4 years has been incredible and the competition was top-notch for 2:13-2:25 guys and 2:40-2:50 women since it was made the US champs course. next year will not be a US champs but I think the reputation it's built will still draw out lots of fast runners next year, although most likely fewer guys under 2:16 and fewer women under 2:40.

the people saying that the net 320 feet of downhill trumps everything else are idiots. a race could climb 15000 feet and then drop 15320 feet and it's not going to be a fast course. now obviously there's a point of inflection where the amount of climbing equals out the net 320', and I really believe that it's close to what CIM has (680' up, 1000' down roughly). A couple years ago I made a thread offering a spreadsheet that I made to CIM hopefuls, with precise mile splits accounting for every hill of the course, for any goal time. I made this using Strava's formulas for calculating grade-adjusted pace. the result I got at the end of my calcs said that a 6:00/mi "effort" on the CIM course, with zero wind, would result in running 5:59.0-5:59.5/mi. So basically I believe that CIM is 13 to 26 seconds (for a 2:37 marathon) FASTER than a perfectly flat course. now, if you add in the fact that your quads get a little beat up from the early downhills (the same reason why Boston feels hard), it probably gets even closer to that perfectly flat course. The results from my analysis also showed that an even split is the best way to run CIM, or to at least be within 15 seconds of an even split.

one last thing - regarding the benefit of drafting. I believe that for a runner running 4:00 mile pace, you're supposed to run about a half second faster behind a rabbit (per 400m lap) than you would solo. so if you are in the OTQ group the entire way and never lead or fall behind too much, that adds up to about 100 seconds of aid at 4min pace, which due to physics would be a little less at 5:00/mi and even less the slower you go (not a linear impact, as it's based on V^2).

2 minutes faster than Chicago? You're nuts.