using garmin in marathons

dnjoyce

I'm running NYC on Sunday and am planning on using my trusty Garmin 405. I was wondering what way people use theirs (or equivalent) during marathons - eg pre-load a 26.2 mile normal run within certain pace, or just check your splits every mile, or use the virtual partner function with your preferred race pace? In Lsr's to-date I have just set the distance and a pace bracket which seems to work ok. Pretty sure the NYC course can be downloaded to the device as Garmin are a sponsor but don't want something I'm unfamiliar with on the day.
The thoughts of Krusty and any other garmin users would be very appreciated!

plodder

Personally, all I use is pace and average pace. Keep it simple.Though I haven't used the watch in a marathon yet.

aero2k

I've mine set to auto lap every mile so I look at average pace to that point, and average pace for the current mile. When I get the "beep" for each mile split I add on 3 or 4 secs to account for not taking the race line. I have a 305 so I display the time in H:MM:SS in big numbers across the top half of the screen - if I lose the signal at least I'll have the time - and I check this every 5 miles or so.
I find the instantaneous pace varies too much to be useful.

Krusty_Clown

I'm a sucker for any thread with the word Garmin in it. Firstly, don't load the course. You're not going to get lost, so I don't imagine it serves any purpose at all (a compass to point you in the right direction?!).

I don't think you can use the virtual partner, or set-up a simple workout with distance=26.2, as neither of these options will take into account your racing line or GPS inaccuracy. It really depends on what your target is. Are you going for one of those milestone times, e.g. sub4, sub 3:30, sub 3, etc?

Best thing to do (in my humble opinion), is have the following fields:
1) Time - Have this as your main field, so that it displays seconds, as well as hours and minutes (and it helps to have this large, for when you're really tired, and cannot concentrate). Print off a pacing band from here and do cover it in sellotape (I learned the hard way!) and attach it to your wrist. Compare the [Time] field with the pace band time, at every mile marker.
2) Average pace - you need to keep this a couple of seconds below your target, in order to meet a milestone goal (e.g. if running for sub3, you need to keep this at around 6:49 instead of 6:51 to account for poor racing line and GPS inaccuracy)
3) Distance - Can be useful, but understand that this is just a guideline for the reason listed above. In Monday's marathon, my Garmin reported the distance covered as being 26.48 miles (on a certified course!).

If you're just planning on getting around the course, I wouldn't worry too much about the above. You don't want to over-fixate on pace, etc., if you're out to enjoy yourself. But if you're a control freak like me, trying to squeeze every last second, then maybe the fields above would work for you.

RJC

Krusty_Clown wrote: »

my Garmin reported the distance covered as being 26.48 miles (on a certified course!).

This got me on Monday as well - 26.39 miles. Some of the splits were at least 0.3 - 0.5 miles away from the mile markers. It makes a bit of a joke of pacing training using one of them.

plodder

RJC wrote: »

This got me on Monday as well - 26.39 miles. Some of the splits were at least 0.3 - 0.5 miles away from the mile markers. It makes a bit of a joke of pacing training using one of them.

I think it's not unreasonable that the mile markers might not be placed exactly right, but I'd be surprised if the course wasn't exactly 26 miles 385 yards (to inches accuracy). Your garmin might have reported a longer distance because most runners follow a slightly longer course than the official distance, which is based on following the absolute shortest line between each bend in the road.

sarsfieldsrock

RJC wrote: »

This got me on Monday as well - 26.39 miles. Some of the splits were at least 0.3 - 0.5 miles away from the mile markers. It makes a bit of a joke of pacing training using one of them.

These may well be correct as you were probably not following the racing line and that extra distance does add up. Pity they don't show the racing line as they do in London so that you can attempt to stick to it.

I was going to try to use the training partner in New York.
I'll set the first 13 miles at 9:10 and then the next 14 at 9:00. That should get me over the line in under 4 hours if I am able to keep up that pace. Just setting it for 26.2 miles is nearly always too short for the marathon.
I doubt very much if I will be able to go under 4 though but hopefully I might do less than 4:10.

--amadeus--

How KC has his set up is identical to how I have mine Nice big time display, total distance and avg pace and you're good to go on training runs or races.

Relying on a Garmin in a race is a mistake - you will *never* run teh true race line and it will always over-report distance. You need to know how far you have raced, not how far you have run. Plus there is always a chance that your Garmin will lose satellite signal half way through a race.

Like anything though a Gramin is a training / racing support tool. You don't need one.

RJC

I'm aware of the racing line and always try to run tangent to tangent (not that it would make much difference to my performance!) I also don't doubt the course distance. It is the accuracy (or the variable accuracy) of the 405 that I identify with. In some other accredited races I have run the 405 beeps within a few metres of the mile marker. I would have thought that the elites and (as Tergat calls them) the club runners would prefer accurate mile markers.

At any rate, my 405 has had a broken light for the past 6 months but now that I have a month of rest and easy running I can send it back under warranty (it's 12 months old at the end of November).

plodder

--amadeus-- wrote: »

How KC has his set up is identical to how I have mine Nice big time display, total distance and avg pace and you're good to go on training runs or races.

Relying on a Garmin in a race is a mistake - you will *never* run teh true race line and it will always over-report distance. You need to know how far you have raced, not how far you have run. Plus there is always a chance that your Garmin will lose satellite signal half way through a race.

Like anything though a Gramin is a training / racing support tool. You don't need one.

I agree, you don't need one. A regular stop watch plus pacing band should do it, but I've found in the heat of the moment, that I've missed certain mile markers, and then lost time during the confusion. But, thinking about it, having the elapsed time on the watch is very important, so what I'd do for my next marathon would be to use a pacing band, and then put time, average pace, and maybe pace on the watch display.