what's the benefit of not wearing a watch during a marathon?

They didn't wear watches because they were racing , not simply doing a time trial - they knew they would be in the front of the pack and pace wasn't going to change that , whether it was fast or slow.

On a totally different note:

I wore a watch in my first marathon and blew up, trying to match a preconceived pace that just wasn't there that day - my next race will be done based on effort

What is the benefit of wearing a watch?

Maybe you might run by "feel" and get a PR?

Doesn't the lead car display the time?

No watch wrote:

I wore a watch in my first marathon and blew up, trying to match a preconceived pace that just wasn't there that day - my next race will be done based on effort

Well there is another side to that coin. I've only done one marathon, so the sample size is rather low, but I ran the first half based on my watch and stuck to my plan within a few seconds on each mile. Felt completely amazing and energized at 13 miles and decided to go off plan, ratchet up the pace a quite bit until I felt like I was working... and crashed hard at mile 23.

I think the marathon is very tough for an amateur to properly gauge. I suspect the pros don't wear watches mainly because they don't have to -- they have a very thorough understanding of both perceived effort and their actual pacing. My understanding is that pro cyclists do use power meters, so perhaps if a legit running power meter ever comes along we'll see a change.

on the other hand... wrote:

What is the benefit of wearing a watch?

Although I agree that watches can lead to you trying to maintain a pace that isn't right for you on the day, I've often found that a watch is good for making sure I don't go to fast at the start. I'm more likely to find I've gone out too fast than gone out too slow, and the watch helps to correct that.

World top runners are supposed to know what's going on, without a watch.

Same reason that 10k, 5k, and other track runners don't wear watches. What I don't understand is where are their little bottles around their waste? And why no iPhones strapped to their armbands? Those are critical to the marathon.

Is it possible that's the reason Kipchoge appeared surprised that he was within :08 seconds of the WR at the finish of the London Marathon? Is it possible he just didn't know because he was running by "feel" and not wearing a watch?

That would be kind of a shame if that were the case. What if he never comes that close to breaking the WR again (though most everyone expects him to)?

I don't recall if he talked about this after the race but it kinda makes me wonder.

When someone asks "what time is it?" I can honestly say "I don't know".

Benefits - a 3:11:45 BQ

Negative - may become invisible to photography

Obviously they are not aware that if it is not on Strava, then it didn't happen.

I've run 2 marathons, both with a gps watch. Unlike the Rupps and Kipchoges of the world, I am not so in tune with my body and so tied into marathon pace that I could lock into the proper paces without a little bit of guidance. This is especially true of the marathon, which is run at a pace at which most people don't run very often. Even if you plug a handful of training sessions that include miles at mp, on race day, those first miles feel much easier than anything you did in training. Also, very few people are running for position in the marathon, most are running for time.

After the first few miles, you have a much better chance of locking in the right pace. The last 6 to 8 miles end up being brutal though, and those are times when I like the feedback from my gps watch.

I would probably be comfortable running my next marathon without a gps watch, but my biggest concern would be toward the latter half of the race, using course clocks to confirm my pace - at some point, when you are fatigued and near your limit but trying to hold on, the math simply gets hard.

I never wear a watch in a marathon. Back in the old days, marathons usually had large digital clocks at each mile or at least at a number of points along the course which you could use to judge pace. I find it hard to read a watch during a race with sweat streaming down my face, etc., and sometimes the watch band chafes my wrist during a long run. Mostly, though, I want to run the way I feel, particularly in a marathon, and not be tied to some specific predetermined pace.

How often do you race? I like this in concept, but just don't think I would get my best possible outcome if I put it into practice.

I could race 5ks watch less based off of perceived effort and my familiarity with how 5k pace feels, no problem. But for someone who has run two fall marathons, on very different courses, and trained for them with a total of 7 or 8 mp runs, all run on dead legs and in the bowels of a hot and humid summer, trying to run by feel alone seems nearly impossible.

I have to imagine you're very experienced at the distance.

on the flip side wrote:

My understanding is that pro cyclists do use power meters, so perhaps if a legit running power meter ever comes along we'll see a change.

There are semi-legit running power meters out there. My understanding is that they're only useful for hills, not wind. In general, though, pace and power are much more closely correlated for runners than for cyclists, so unless the power meters are extraordinarily accurate, I doubt they'd be an improvement on just taking mile splits, unless you're on a very hilly course.

The weight of the watch would have thrown Rupp off balance. He needs to maintain his perfect running form.

It is foolish for fast runners like myself to wear watches. They cut down on the aerodynamics of my arm swing as well as the overall aerodynamics of my body as I slice through the headwind produced by my incredible speed.

Is is probably the same story for those wannabe speedy marathon runners too.

Feyisa Lilesa didn't wear one either. 1-2-3 sweep for the watchless. In a tactical race in unpredictable weather on a course with many turns, every km split is going to be different...

Funny. Your kids calling Rupp an experienced marathoner. Funny.