Posted by: Ian | January 22, 2012

My Garmin 800 – I love it, I hate it!

I wrote last time about the exercise protocols that I’m following as recommended in my metabolic assessment. They’re excellent. Yesterday, for example, I did a 3 hour endurance ride, trying, as far as I could, to stay within the sub-threshold heart rate zone determined by my test results (110-149 bpm). I’ve read about base building before and been sceptical – I worry that, since my cycling is unstructured, riding more slowly would simply lead to me losing any conditioning that I have. But at the end of my ride yesterday, I could see how just doing longer and longer similar rides, together with some more specific hill training in Spring, would set me up well for the events I’ve got lined up later this year. The problem is that riding more slowly takes more time, and then adding more distance takes longer still. For example, my 46 miles yesterday took me three hours – 100 miles at the same pace, especially if I stop for lunch, would take all day, which is half of my weekend.

My other problem is the practical one that I wrote about before: the heart rate information on my Garmin is often grossly wrong. Yesterday actually it wasn’t too bad, but look at the output I got last weekend when I was doing anaerobic intervals on the turbo trainer:

The flatish part at the first 10 minutes of each of the charts represents me waiting for the 800 to report my heart rate at a correct/survivable level. In fact, I’d been kicking around doing not much at all for some time before this, waiting for my HR to stop oscillating in the 220-250 bpm range. It didn’t, so I got on the turbo trainer, hoping that after a few minutes of gentle pedalling I’d get a sweat up and then it would work.

The part where the HR chart goes into a linear downslope is me taking the damn thing off and trying Paula’s. That showed numbers that I could use for my work-out; then, after three intervals, my own one was showing usable numbers too so I switched back to that.

You can see the form of the exercise – I pedal at a cadence of about 115 rpm, corresponding to something over 500W, until my HR gets to 160 bpm. Then I take it easy until I reach a recovery rate of 134 bpm. Then I start again. Within a 20 minute window I managed this twelve times. The goal is to be able squeeze in more as I get more conditioned.

I confirmed that I don’t have an exotic heart abnormality by wearing the Garmin while I was on a gym bike that measures my heart rate through metal plates in the handlebars. While the Garmin was off in the 200’s the gym bike was showing normal readings of, say, half of that. Looking online, I see that this is quite common and I’ve tried all of the proposed remedies. Naturally, my first recourse was to change the battery in the strap. I also tried licking the electrode pads on the strap. And I tried using my old Garmin 500, which had the same problem, confirming my view that the issue is with the strap itself. After all of that, I tried the more quixotic ideas from the web: moving the strap to the side so that it sits differently on my ribs, then trying having the electrodes at the back; putting the transmitter on upside down; dampening the strap; applying electrode gel. None of these changes brought the slightest improvement. The only path that seems to have led to some kind of increase in stability has been washing the strap after every ride.

Since the Edge 800 is effectively unusable for protocols that require a semi-accurate HR reading, I decided to press my power meter into greater service. I use it on the turbo trainer but tend not to use it so much out of doors, if only because (a) it means swapping over the turbo-specific tyre for a road tyre and (b) the Mavic OpenPro into which the CycleOps PowerTap unit is built is my least exciting road wheel. Neither of these issues is a big deal.

To prepare myself for a few weeks of power-based training, I set out this morning on my Felt (with PowerTap wheel) to assess my CP30: the critical power level that I can hold for 30 minutes. In all of 2011 I only had one session on the road of about this duration when I had the PowerTap on the bike. Then, I had managed an average of 264W; this morning I was hopeful that I could improve on this. At about 9 am Paula and I drove out to the car park at Staple Hill and set off on the level roads around Smeatharpe. We rode together for about half an hour, and then I saved that part of the ride as a separate warm-up activity on my Garmin. Then I upped the power and increased speed while Paula carried on with her tri training. Ironically, my heart rate readings were fine: in the warm-up I was averaging around 130 bpm with no rogue high values, and during the power phase my heart rate showed a stable and credible 170.

Exactly 30 minutes later I hit the Stop and then the Reset button on the 800 to save the ride. When I tried to load it to see my stats the unit froze. It often does this when scrolling through the maps page; it’s a known defect and hitting the power button to bring up the brightness settings usually restores control to the screen. This time it didn’t. When I tried turning it off and on again it wouldn’t re-start at all, hanging on the “load maps” message.

Back home, I can retrieve the FIT file off the device but it won’t load into Garmin Connect or Garmin Training Center or Golden Cheetah. Nor can I find a Mac-compatible utility to load the FIT file into non-binary format or to repair it. There’s a PC-based programme that looks just the ticket and the guy who wrote it very kindly says he’ll have a look at my file for me tomorrow. I’m more hopefully of hearing from him than I am of getting anything from Garmin Support, but you never know.

Meanwhile, my G800 is unusable. When Emily had the same problem (it’s not just me) she had to delete all of her courses, and then it worked again. I tried that and it hasn’t worked for me, though I suspect that if I delete all of my activities, or even just the corrupted last one, the device might lurch back into life. Until it does, I’ll try using my old Garmin 500. In London, that means cycling for miles while its ineffective GPS locater fails to find any satellites – a feature that’s much improved on the G800. Despite the thing driving me up the wall, it’s so useful when it works that I’ll have it going again by next weekend, even if I have to resort to restoring factory settings.



  1. […] I’ve written before, my Garmin 800 routinely shows stupid-high heart rate readings. I used to notice this most […]

  2. I’m glad I’m not the only one having issues with the reliability of the Garmin devices – or more precisely their software. My current tally runs at:

    405: unexplainable freezes, unreliable HR measurements, very short battery life, backlit not working

    61st: unexplainable freezes, very bad menu and functionality, inability to update map on my desktop.

    If the Polar GPS Pod wouldn’t be so clunky I would switch back tomorrow!

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