Tuesday, November 19, 2013

The Garmin 620 on the treadmill

Yesterday morning, when I woke up, the power was still out. The wind was blowing like crazy (which is what knocked the power out on Sunday evening), and I was expecting trees to start blowing onto our house. The last thing I wanted to do was go run in that wind, so I decided to run on the treadmill.

Yep, I guess I'm not the sharpest tool in the shed, because I thought, "Oh, I can't run on the treadmill, because I won't be able to watch TV or anything to keep my mind occupied!"--because the power was out. Then I had the idea to listen to my iPod, and just stare at the wall while running. I was only planning to run three miles, so it couldn't be too bad.

[No, it still hadn't occurred to me that the treadmill itself uses electricity...]

I got completely ready to run on the treadmill, turned on a podcast to listen to, and looked forward to the "adventure" of running on the 'mill without watching TV. When I turned on the treadmill, nothing happened. It was only THEN that I thought, "Duh! I can't use the treadmill, because we have no electricity!" And here I thought I was getting creative by using my iPod instead of a TV show, hahaha.

The power came back on at around 3:00 in the afternoon, so I ran on the treadmill then. I was excited to see how my new Garmin would do as far as accuracy. There is no foot pod; the distance is measured with the accelerometer in the heart rate monitor. I decided to do three miles at three different speeds, just to see what would happen.

For the first mile, I set the treadmill at 6.5 mph, which is a 9:14/mi pace. The Garmin showed that I ran that mile in 9:30; that was a pretty big difference, but I figured that it took at least 5-10 seconds for the treadmill to get to that speed.

For the second mile, I bumped the speed up to 7.0, which is an 8:34/mi pace. I definitely felt like I was running at that pace; my heart rate went up, my breathing was harder, and I was sweating like expected. But the Garmin showed that I finished in 9:20. That's a HUGE discrepancy! I know I was running much faster than 9:20, just based on my heart rate alone.

For the third mile, I lowered the speed to 6.0, which is a 10:00/mi pace. My heart rate lowered a lot, I felt like it was very easy, and just how I expected a 10:00/mi pace to feel. According to the Garmin, I completed that mile in 9:44.

Incline shows 0, but it was at 1% while running


The treadmill showed that I ran 3.11 miles in 28:48, which is a 9:16/mi pace. The Garmin showed 3.00 miles in 28:34, which is a 9:31/mi pace. I started my Garmin about 10 seconds after the treadmill, so obviously the timer on the treadmill is slightly off (which I knew already).

I'm disappointed that the Garmin was so off with the pace! I know the treadmill isn't perfect, but the Garmin definitely should have shown a bigger distinction between each mile. My pace graph usually goes parallel with my heart rate; the faster I run, the higher my heart rate is. But that wasn't the case on the treadmill. My heart rate reflected the faster pace, but the Garmin barely registered it.



All of the other stats (vertical oscillation, ground contact time, stride length) were right on with what they have been outside. So, I'm not really sure what to make of this yet. It was only a three mile run, and the first time I'd used the new Garmin on the treadmill, so I'm going to experiment some more with it. Maybe I'll wear both Garmins on a run (the 910 with the foot pod, and the 620) just to compare.

If it continues to be inaccurate, I'll just have to pair my foot pod with the 620; but that would be a bummer, because I was excited to ditch the foot pod!

I took a rest day today. I'd like to switch my rest days to Tuesdays, because my weigh-in/the start of my new Weight Watchers week is on Wednesday. When I have a rest day on Wednesday, I don't have any activity PointsPlus to start off my week, which is tough. So if I make Tuesday a rest day, I can plan to use up the rest of my weekly PointsPlus before my weigh-in the next day.

Speaking of which, I've stayed on track all week long, so I'm actually looking forward to weighing in tomorrow :)

30 comments:

  1. I actually laughed out loud when I read you were trying to run on the treadmill when the power was out. haha

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    1. Yeah, sometimes I just don't think things through! ;)

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  2. The TomTom Runner GPS watch that I had for about a month (and used similar internal accelerometer technology) was WAY worse than that. The distances indicated (and, therefore, pace) were not even close. There was a "treadmill calibration" menu with the TomTom Runner that you were supposed to use the first few times (although it never seemed to capture and retain that data, a bug that I think has since been fixed with a firmware update). Does the Garmin have anything like that? Didn't you have to calibrate the footpod/Garmin manually as well?

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    1. From what I've read on the Garmin 620, it sounds like it uses the data from your outdoor runs to calibrate the accelerometer. I'm hoping after quite a few outdoor runs, the accelerometer will get a more accurate reading on the treadmill... we'll see!

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  3. I was wondering if a Garmin would be effective at all indoors. Hubby has one and I know it tracks distance via GPS, it's an older model so I do think that might be all it does (although it does have a HRM too). My elliptical and stationary bike do NOT use electricity ... they are powered by the movement (so they don't hold your numbers for very long if you stop) but I would be able to workout, even if the power was out ... although I would miss my TV. I could read a book or listen to music though ...

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    1. That would be nice to have in a situation in bad weather when the power goes out. Our electricity goes out a LOT, which is ironic, considering we live next to a nuclear power plant!

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  4. From what I've read on DCRainmaker, the accelerometer in the heart rate strap gives you running dynamics like ground contact time etc, and the internal accelerometer in the watch itself gives you your pace and distance. He noticed the same thing as you on the treadmill, but thought that it might have to do with the amount of arm swing, and that it is most accurate when running close to your typical pace. The internal accelerometer is one of the main reasons I chose to order the 220, so I hope it ends up working ok - a lot of my running is on the treadmill!

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    1. That's interesting! I'm not sure why I thought the accelerometer was in the heart rate monitor. My arm swing is definitely a little different when I run on the treadmill, because I'm trying to avoid hitting the display; also, I was looking at my Garmin quite a bit, which made me stop swinging my left arm so much. Next time, I'll try and swing my arms the same as I would outside, and see what happens.

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  5. Haha that's hilarious. Sounds like something I would do. Although I hope I would have realized it before stepping on the treadmill (although let's be honest, I probably wouldn't have).

    Bummer about the Garmin. Although, you always said you thought running on the treadmill was easier than outside. Maybe your treadmill is "inflating" your pace and has been all this time. I certainly wouldn't trust the Garmin output, but maybe the truth is somewhere in the gooey middle.

    You'll have to find another treadmill and test it out!

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    1. That's very possible! But my foot pod is extremely accurate (I calibrated it on a 400-meter track), and it's extremely close to what my treadmill reads. So I think the treadmill is actually more accurate than the Garmin 620 (for right now, anyway).

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  6. I often wonder if Treadmills don't get "slower" over time? If they don't uncalibrate themselves so to speak? Oftentimes at the gym I feel like some treadmills feel slower to me at the same pace as others. So you bump up the speed, but if the motor is worn out some, is it really going as fast as it needs to? I don't know. Food for thought I guess. I was finally able to order my 620. I can't wait to get it and I really hope the treadmill aspect is somewhat close. It's interesting to me cause my HR monitor (polar) says I burn about 500 calories in a 3 mile run - double your burn. I wonder what the Garmin will tell me?

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    1. Yes, treadmills are rarely 100% accurate. But there is a BIG difference in the way an 8:34 pace feels versus a 9:20 pace. If the difference was a matter of 10 seconds per mile, it wouldn't be a big deal.
      My calorie burn used to be that high! I wish it still was, but as I've gotten more fit, the calorie burn went down. I'm lucky when I burn 90 calories per mile now!

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  7. I have been having such a hard time getting my foot pod to stay calibrated I was looking to sell my 910 and get the 620 just to ditch the foot pod so I am glad you did this post.

    No matter what I do I can not get my foot pod to be accurate!

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    1. This is nerdy (even for ME), but it's how I calibrated my foot pod, and it's spot on every time! http://www.dcrainmaker.com/2011/06/garmin-ant-footpod-calibration-tool.html
      It was easier to use than it looks! ;)

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  8. Maybe this is a silly question, but...why do you need a Garmin on the treadmill at all? One of the small joys of treadmill runs is that the treadmill keeps track of your distance and pace, non?

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    1. Not a silly question at all! It's probably a little ridiculous that I love to look at all the numbers when I'm done running, but that's why I like the Garmin. I like to use it for my heart rate, cadence (steps per minute), splits for each mile, etc. Also, it's easier to upload the info to the computer when it's on my Garmin, versus when it's on the treadmill. But yes, I *could* just skip the Garmin altogether on the treadmill, I just don't want to! ;)

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    2. Ah, a number junkie. I understand. : )

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  9. Maybe you need to do more runs with it outside before it's properly calibrated?

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  10. You're not the only one! I'm in Ohio and we had some crazy weather recently - and when we last lost power, I thought - Wow what a great excuse to work out! I can't watch TV or go online, so I may as well run on the treadmill! And of course - it didn't work. Such a let down!

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  11. Something I have learned to accept is that satellites, treadmills, footpads nor apps aren't perfect. I used to get so incredibly frustrated when I realized my tracking app was off during my run. But I decided to always do what my readout says, even if I might be running an extra tenth of a mile. I tell myself all these things are just guides to help get me to the start line of a race, and that helps!

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  12. I am cracking up at you thinking you would run on the treadmill with the power out...if it makes you feel better, today the power went out at my aunt's house, but when I stopped by to wish her a happy birthday, she wanted to show me my grandmother's old stereo from 1943 (the big one with both a radio and record player). She said, "It still works, let me show you..." She plugged it in and we were just befuddled when it didn't work. It was only when my mom came over that we were discussing it with her that my mom said, "Well of course it doesn't work--the power is out!" ;) Thanks for letting me know I'M not alone!

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  13. I'm glad to find this site since there's not a lot of info from real runners on the new Garmin 620. I have raced twice with my 620 and on both races, the 620 was at least 3.5-4.0 minutes off race time posted. Also, I have my 620 set to alert me every mile, and it alerts between .04 - .08 seconds faster than the posted mile marker on the course. Of course, a race course is not perfect, but I also own the Garmin 610 (with HRM & footpod) and it kept time & distance almost spot on for every race I've done. So I'm not sure what the deal is with the new 620. It is starting to irritate me because not only is the watch very expensive, it's main function is suppose to keep accurate time. I am starting to suspect that the 610 combined with footpod is more accurate versus the 620 combined with the HRM/accelerometer. I have not seen anywhere where the 620 needs calibration. I did that with 610 when I paired it with foot pod. I already opened a case with Garmin and waiting to hear back.

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    1. We could probably turn this into a nice long forum about the 620. I just got the 620 myself after being a 5 year user of the 305. I found the 305 to be extremely reliable and consistent but decided to get the 620 because what else could you ask out of a watch with all the new features it has!? Not wanting to say goodbye to my old 305 just yet, I've wore both watches. Over 8 runs in 3 different states on vastly different courses, the 620 read 0.2% lower in distance. One particular run troubled me where the two watches tracked each other perfectly then the 620 suddenly lost 0.05 miles to the 305. I believe the difference comes from how the two watches use the smart recording feature. Looking at the raw TCX files of the run in question from both watches, the 620 captured about 100 less data points or 20% less than the 305. How could that not effect accuracy?? And its obvious the two watches use a different formula for smart recording. The internet is filled with people saying that 1 second recording doesn't improve accuracy, but how could it not? I just completed an 8 mile run with both watches set to 1 sec recording and they tracked each other dead on throughout the entire run. I'll do this experiment for another week and call it a day but I believe if you're after a super high degree of accuracy, especially in a race with lots of turns, you have to use 1 second recording. I've also had the same experiences as Katie using the watch on a treadmill. Its inconsistent and when you run lots faster, the watch doesn't read lots faster. So I broke down and bought a footpod. Just calibrated on a local track using the default settings while running five 800m runs. It was off by 0.005 miles. Not bad!

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    2. Thanks for the input! I set mine to the one-second recording from the get-go, so I never noticed the distances to be "off". But that's interesting to know! I haven't had any issues with accuracy as far as distance or pace outside, but the treadmill is definitely a problem.

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  14. I had the same experience with the FR 220, it being 0.3 miles under from what the treadmill showed. The accelerometer is in the watch itself, rather than the heart rate monitor.

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  15. Sorry if this appears multiple times, having trouble posting my comment! I wanted to say I had the same trouble with the FR 220. It was about .3 miles under from what the treadmill said. Also,the accelerometer is in the watch itself, rather than the heart rate monitor.

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  16. Thanks for this post! Did you have to turn the GPS off to run on the treadmill? I started running with my 620 on a treadmill but it kept going to auto-pause since it didn't sense I was moving. I turned off the GPS and then it was fine but I'm wondering if I needed to do that.

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  17. Thanks for this post! Did you have to turn the GPS off to run on the treadmill? My 620 kept auto-pausing because it didn't sense me moving but it was fine after I turned off the GPS.

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  18. I just wanted to mention that you have to take in account that what a treadmill reads is not what your pace is going to be with mileage. If I were to run on a treadmill at a certain speed and have long strides...the treadmill will read more miles than what my stride is doing. Over a period of time this will make a significant difference in mileage.

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    1. ^^^ what you're saying makes absolutely no sense whatsoever.

      Say in a given treadmill, the total belt's length is 9ft, and it takes the belt 0.5sec to go one full loop. That is a linear speed of about 10mi/h.

      Say you ran at that speed w/o falling off the belt...

      Your pace would be... take a guess... 10mi/h... SURPRISE or rounding up to 5min/mi to make it easier.

      It doesn't matter if you take large strides and your cadence is 150 spm, or your strides are short and cadence is 225 spm. You're still staying on top of a belt running at 5min/mi. Same as if you run outside, you can run at the same speed/pace while varying stride+cadence. Not too difficult to figure out, really.

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I'd love to hear from you! I read all of my comments, and if you have a question, I do my best to respond; sometimes, however, I get busy and forget to go back to reply, so if it's important, just email me! :)