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GPS sport watch settings for road running races & the Boston Marathon

A GPS sport watch like the Suunto Ambit3 Peak and Garmin Fenix 5 offers pace, distance, heart rate and other data on a current, average, cumulative, and lap basis.

I consider my GPS watch an indispensable tool for training and racing, especially in longer events like marathons and trail ultras, when early on I need to remain patient and to run within my abilities so that I don’t blowup later in the race and hemorrhage time (or DNF).

Customizable displays

One of my favorite features of my Suunto Ambit is the ability to customize its displays. This is done in the owner’s Movescount profile. Garmin GPS watch displays are also customizable, but I’m less familiar with the process.

With customizable displays, I can specify exactly what data I want visible. For example, I have created different displays for ultra-marathons and for backpacking. In this post I will detail the displays I used recently at the Boston Marathon. These settings are equally applicable to longer road races like the 10K and half-marathon.

Prefacing remarks and notes

Before I owned a GPS sport watch, I used a pace chart with split times. I could memorize a handful of splits (e.g. for a 1- or 2-mile race on the track) but it’s virtually impossible to memorize splits for longer races. At that point, a laminated print-out must be carried or worn. With a GPS sport watch, I can leave the pace chart at home. I simply memorize the necessary pace to achieve my goal time. I also memorize a slower “baseline” pace and a faster “best case scenario” pace. During the race, I need only glance at my watch — which can display my average pace — to know whether I’m on pace, or faster or slower.

You can trust the mile- and 5K-markers at a well organized race like Boston, but not the street clocks. The clocks start when the gun fires, but in a large race you may not cross the start line for minutes or even hours later.

The auto-lap feature on your watch also should not be trusted. It may be accurate, but it probably does not synch perfectly with the exact course, which is the most efficient line from start to finish. You will probably run longer, because you’re unable to match this line, especially in a crowd. Even if you run 0.01 miles longer per mile, that amounts to 0.26 miles extra over the course of a marathon, which equals about 90 seconds if you are holding 6-minute pace.

The Garmin Fenix has a “Finish Time” calculating feature. I haven’t used it, but it might be worth testing. Late in the race when you are deeply fatigued, it can be difficult to remember even just a few pace/finish time relationships.



Sport Mode settings

In Movescount, “Create a new sport mode.”

Give it a relevant name, like “Boston Marathon.”

For the Activity, select Running.

Scroll below for Display instructions.

Recording interval: 1 second

GPS accuracy: Best (GPS ping every 1 second)

Pods to search: If you are using a heart rate belt, check that box.

For this application I would leave alone the advanced settings. The defaults are fine.

Display 1: My pick

Screen 1: Pace

  • Top: Chrono
  • Main: Pace
  • Bottom: Average pace, Lap average pace, Heart rate

Screen 2: Heart rate

  • Top: Chrono
  • Main: Current heart rate
  • Bottom: Average heart rate, Pace, Average pace

Display 2: My picks with a split twist

Even at Boston, which is known its downhill start and rolling Newton Hills, it is possible to maintain a fairly steady pace from start to finish. My slowest and fastest 5K splits, for example, were separated by just 20 seconds per mile, and both were within 10 seconds of my overall average.

A mountain ultra race is entirely different, due to the variability in vertical and footing. For example, at the San Juan Solstice last year I ran one 7.8-mile section at 9:18 pace and a 3.3-mile section at 16:51 pace.

So at Boston, I chose to focus primarily on current and cumulative data, not split data between mile or 5K markers, even though I hoped to run a strong negative split.

In Display 1 above, I added just one split data field: Average lap pace. By hitting the lap button at the halfway mark, I had a “fresh” average pace for the second half. However, I don’t recall consulting it often: by that point I was mostly running by feel, and with about 10K to go it was a full-out redline, pace be damned.

All that said, if you want to watch your mile or 5K splits more religiously, this is what I would recommend:

Screen 1: Pace

  • Top: Lap time
  • Main: Pace
  • Bottom: Average pace, Lap average pace, Heart rate, Average heart rate

Screen 2: Heart rate

  • Top: Chrono
  • Main: Heart rate
  • Bottom: Average heart rate, Pace, Lap average pace

Display C: No heart rate

I am an avid user of heart rate, in both training and racing. Most importantly, the data helps me to govern my pace during long intervals or races, when starting too aggressively can have disastrous results later on.

Versus other senses, my HR is less likely to lie. In contrast, my legs feel fresh and spritely after a race taper. And early on in a long effort, my body is not suffering from muscular fatigue or glycogen shortages — but it will eventually, and by monitoring my HR I can ensure that I don’t reach that point too early.

If you are not a HRM user, my recommended changes to my recommended display settings should be obvious: eliminate any HR-related field, including the entire second screen.


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8 Responses to GPS sport watch settings for road running races & the Boston Marathon

  1. Jakob April 25, 2017 at 7:16 am #

    I actually like doing the pace calculations in my head during the race. It’s a nice distraction that let’s some time pass.

    • Andrew Skurka April 25, 2017 at 8:16 am #

      Man, you must be better at math than me, or try to run in very even numbers, e.g. exactly 6:00 or 6:30 pace.

      Last year at CO Marathon Steve and I tried to calculate some splits. By the time we came up with an answer, which was of questionable accuracy at best, we had already reached the next mile split. It was certainly distracting, but too frustrating for me.

  2. Matt April 25, 2017 at 11:19 am #

    I think this pace prioritized config is great, but for training and in general running (which includes the trail running aspect), my settings are:

    Disp 1:
    top:HR
    Middle: current pace
    Bottom: Distance, Time of Day, Chrono, and Avg Pace (battery charge if on longer runs)

    Disp 2:
    t: Temp
    m: altitude
    b: vert speed

    Disp 3:
    Barograph

    Disp 4:
    a. avg pace
    b. current avg speed

    I generally dont like to cycle the main displays since its distracting to remember what each display is unless its really obvious, hence the simplicity of the other displays. The first display being the one that’s up 99% the time and I just cycle the bottom to see other info tidbits while on the go. Anecdotally, I’ve found that not glancing as frequently has me at a steadier HR at tighter paces than looking over more often, so it’s probably best to run by feel in general (Alpinist Steve House specifies breathing patterns as a great way to generally dictate what zone you’re in/where you want to be)

    thanks for your write up!

    • Andrew Skurka April 25, 2017 at 1:21 pm #

      For training runs I use something else, too. The specified race display would be useless for a track workout or a mountain run, for example.

      • Amir May 2, 2017 at 6:54 am #

        Thanks Andrew. Great info. When doing stride workouts is there a way to keep track of stride times and number using the ambit? Thanks

        • Andrew Skurka May 2, 2017 at 10:07 am #

          You can customize the display in order to show lap number or lap time. But here is what I have found more effective:

          1. Create the workout so that the strider and the rest equals a whole number. For example, 20 sec stride, 40 sec rest (=1 minute); or 60 sec stride, 60 sec rest (=2 minutes). Avoid combinations that end with :15 or :45, and even :30.

          2. When you start the striders, start a new lap or simply start when your chrono hits a round time, like 26:00.

          3. Just do the math in your head. Today, for example, I have 15 x 60/60 on the road. The whole workout will take 30 minutes, with my last hard effort starting at the 28-minute mark. I’m more than halfway through at the end of the strider that starts at 14 minutes. When I have tried to use the lap button for every strider, I tend to get lost in the laps.

  3. Knut April 25, 2017 at 11:41 am #

    Thanks for sharing, always fun to see what other athletes do.

    The “Finish Time” feature you mention suffers from the same basic issues that you mention just before and would not be recommended, at least not for longer races.

  4. Derek April 25, 2017 at 12:02 pm #

    I train with an Ambit 3, but when I race I like to go watchless. I like to think that I’ve done enough race-specific race pace training that I don’t need the reassurance. Plus, the Ambit 3 is a bit heavy.

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