GPS Accuracy Test - Ionic vs. Surge

[shipo]

First off, apologies to @SunsetRunner for basically stealing and cannibalizing the title of his thread, but it seemed appropriate in this instance.  🙂

Over the last six to eight weeks there has been much speculation regarding any improvements in the Ionic's GPS tracking sensitivity compared to the Surge.  Having logged many hundreds of runs covering well over 4,000 miles with a Surge, I have a pretty good feel for the Surge's accuracy level and where it loses some accuracy (mainly on turns and curves).  My initial take on the Ionic in the nine days I've had it during which I logged eight runs in that period, is that its granularity of fixed points along a route is significantly higher than the Surge.  Said another way, the track images generated by the Ionic don't show the same "shortcuts" in curves and around corners the images from the Surge showed.

With the above in mind, my last three lunch time 10-mile runs with the Surge and the first three on the exact same route with the Ionic are summarized below:

As you can see, the variance with the Surge was 016 miles while the variance with the Ionic is only 0.03 miles; said another way, the Ionic is much more consistent in its measurements.  🙂

[datalore]

Man, how many days a week do you run? 

[shipo]

---

@datalore wrote:

Man, how many days a week do you run? 

---

Anywhere from four to eight (in other words, I might put in two runs on any given day).  🙂

[datalore]

I want to be like you when I grow up. 

[shipo]

I know this might sound crazy (Hey! I resemble that remark!), last fall I got roped into a "Fun Fit Fall Challenge" team for my company; I had a good training base up through the end of September 2016, so I decided to let it all hang out and see if I could run my first 300 mile month of my life.  I ended up logging 345 miles in October 2016, and then followed that up with another 330 miles in November.

I was  hoping to use that training to springboard myself into a good racing season during my first year in my 60s, unfortunately a recurring hip injury I sustained back in 1976 decided to pay me a visit last spring and my mileage dropped off to almost zero in May and June.  July and August were used for gradual rebuilding, and finally by September I started feeling normal again.  So, maybe next year I can let it all  hang out as a relative young punk in the 60-69 age groups.  🙂

[datalore]

I'm never responding to you again, you make me feel like a complete slacker! 

[shipo]

No worries, you still have decades (if I remember correctly) to beat me at my own game.  I didn't start running again on a limited basis until I was 52, and then after several fits and starts, finally getting my full-time mojo back when I was 56.  The thing was, after not having run much in the previous ten years, I had gained nearly 100 pounds of weight, much of which I have yet to lose.

Here's what I looked like in May of 2013, a week before my 56th birthday (after finishing a 5K in a rockin' 45 minutes), and then a year later, two weeks before my 57th birthday (on the home stretch of my first 5K of my 50s under the 22:00 threshold):

[datalore]

Just when I decide to unfollow you; you decide to give me an inspirational story and something to shoot for in the years to come? Now I really want to be like you when I grow up!

[pedris]

GPS / route map seems more accurate on the Ionic than the Surge. Unfortunately, on my runs so far, the pace rearing has been all over the place. I'm doing a half marathon on Sunday and very much doubt it be much use to keep me in the 4:10/km - 4:15/km range. And - for some reason - the kilometre alerts have a lengthy (10 seconds?) delay. Is there any way to change this? Finally, it'd be nice if we could get cadence info, but I suspect the step counter might not be accurate enough for a reliable reading.

[shipo]

---

@pedris wrote:

GPS / route map seems more accurate on the Ionic than the Surge. Unfortunately, on my runs so far, the pace rearing has been all over the place. I'm doing a half marathon on Sunday and very much doubt it be much use to keep me in the 4:10/km - 4:15/km range. And - for some reason - the kilometre alerts have a lengthy (10 seconds?) delay. Is there any way to change this? Finally, it'd be nice if we could get cadence info, but I suspect the step counter might not be accurate enough for a reliable reading.

---

Hmmm, I coach a number of runners who run at your pace; I would think if you're well enough trained to run a half marathon at a 4:10 per kilometer pace (i.e. a 6:45 per mile pace), you would be able to naturally set your pace for that distance on that day for the existing conditions.  The thing is, conditions and courses vary, I've found runners who pick predetermined paces have a two in three chance of doing themselves a gross disservice.  Two out of three?  Yes, consider the following:

1. Your predetermined pace is spot on and your cross the finish line as you reach near exhaustion.
2. The weather conditions and/or your training are better than you planned on and you have too much left in the tank as you cross the 20-Kilometer mark, and you end up running a slower race than you could have.
3. The weather conditions and/or your training aren't as good as you planned, and you bonk at the 18-kilometer mark.

If I was your coach I would recommend you turn off all alerts and just use the tracker to record what you did.

[pedris]

I find accurate pace info useful to:

- ensure I don't go out too quickly (3:55/km or faster), which is easy to do when the starter gun goes off and the pack surges forward!

- maintain consistent pace over the second half of the race, where losing 5-10 seconds per km can be the difference between a 1:26 and 1:28.

[shipo]

---

@pedris wrote:

I find accurate pace info useful to:

- ensure I don't go out too quickly (3:55/km or faster), which is easy to do when the starter gun goes off and the pack surges forward!

- maintain consistent pace over the second half of the race, where losing 5-10 seconds per km can be the difference between a 1:26 and 1:28.

---

Then again, sticking to a predetermined pace might also mean you don't negative split; you might well run a 1:26 when you could have run a 1:24.

[Donnamt16]

i always suspected my blaze was kinder on distance because it always had me going further than map my walk and ofcourse my pace was amazing.

ive walked the same route 3 times this week and the ionic gave me the same distance exactly where the blaze used to vary a fair bit. sadly for my ego i now walk less and slower haha but the gps seems very accutate and i am happy with that

[shipo]

---

@Donnamt16 wrote:

i always suspected my blaze was kinder on distance because it always had me going further than map my walk and ofcourse my pace was amazing.

ive walked the same route 3 times this week and the ionic gave me the same distance exactly where the blaze used to vary a fair bit. sadly for my ego i now walk less and slower haha but the gps seems very accutate and i am happy with that

---

Yeah, I've noticed the runners I train with who use Connected GPS routinely log different distance runs than my (former) Surge and Ionic.

[bbarrera]

I walk and hike and cycle, and have found apps on my phone are very accurate. Fitbit’s connected GPS is inconsistent, sometimes accurate, sometimes not. Even Fitbit’s MobileTrack is more consistent and accurate than connected GPS. I think Fitbit should have implemented Connected GPS using MobileTrack, and only using Blaze as a display. That would have fixed the accuracy problem at the price of not always having the most accurate info in real-time on your wrist. Better deal than having screwed up splits/mileage to review after a workout is done. 

[pedris]

@shipo: I normally run an even to slightly negative split, but that's a decision to be made about 8km - 12km in tomorrow - hopefully with accurate data from my Ionic!

The course is flat and the weather conditions should be warm with a breeze. For me the event is a final tune-up race before the Frankfurt Marathon in two weeks. I'm not shooting for a PR, but do want to be able to stick to my upper marathon target pace for the duration.