Back in August I wrote about my frustrations with running performance. At that time I thought I could improve my pace by pushing my heart rate beyond my typical 75% of Max. After seeing some very weird numbers coming from my FR35, I figured I was either experiencing a medically concerning pulse or there was something wrong with the device that captured my heart rate. To get the details, see below.
My Garmin lied and the truth hurts
|My Garmin made up most of this route|
Today’s run (street): 3.75 miles
Halfway through today’s run, I glanced at my Garmin and saw that I had covered two miles in about 17 minutes. That would have put me on track for my best training run in memory. I was puzzled because my perceived effort was nowhere near what I’d expect for that pace. I tried to rationalize the reasons for such a dramatic improvement in my performance compared to yesterday. It was 10 degrees cooler and cloudy, but could that account for running over a minute per mile faster?
When I got home and saw my time and mileage on the Garmin, I thought I’d rocked it. Maybe I was turning a corner with my training. After all, I used to regularly average 8:45 paces on my daily runs. Breaking 9:00 minutes on a run these days is a notable achievement for me. I hoped it was accurate and not some weird Garmin fail.
Despite that wishful thinking, it did turn out to be a badly confused GPS. For some odd reason, the Garmin put my starting point 3 miles north of where I began my run. Looking at the run data through Garmin Connect, my course appeared to have frequent 50-foot elevation changes. That’s definitely not the case for my relatively flat route. I’m guessing that the low cloud cover may have interfered with the GPS signal and caused it to skip.
I Gmapped my route and was disappointed to see that I’d only covered 3.75 miles, rather than the 4.35 that the Garmin said I’d run. I wanted to run 4-5 miles today and thought I’d met my objective. The good news is that I beat yesterday’s pace by 42 second per mile. The other good news is that it’s a long weekend and tomorrow we’re hosting a Runsketeer pool party. If the weather reports are accurate, the skies will be clear and I’ll be able to get in a longer run in the morning.
Cadence increasing, visibility high
|Artist’s rendering using Google Maps street view|
Today’s run (street): 3.3 miles
I missed Tuesday’s run and needed to make it up today, although the Higdon plan called for a rest day. I felt ambivalent about today’s workout and whether to go easier this morning after yesterday’s semi-fast run. My motivation for speed was low, so I decided to let my level of intensity play out as I ran. Once I got the door I noticed the cold, but the winds that made Wednesday’s conditions feel like 24°, were no longer a factor.
My Garmin hasn’t performed well lately in terms signal accuracy, making my real-time pace data suspect. I’ve been running by feel and heart rate which seem to provide more useful feedback. The type of workouts that I’ve been doing over the last five weeks have helped me increase my cadence. As a result, I’m finding it easier to hold a decent pace on shorter runs. I kept my heart rate around 85% today and ended up running my distance in the high 9’s. That’s exactly what I wanted to do.
Today’s run was unremarkable, except at one point when I was running down a long road near my house. I spotted my wife’s car heading in my direction. She and the kids were going out to do errands and when they passed me, the windows were down and they were cheering for “The Emerging Runner.” They saw me from a distance because I was wearing a bright orange running shirt. High visibility isn’t just for safety!
Lies, damn lies and Garmins
|Look how fast I didn’t run!|
Today’s run (street): 3.4 miles
I was in meetings all day on Tuesday and didn’t get a chance to do a run. I did cover a lot of ground on foot, so that should count for something. Along the way I noticed many marathon tourists (after all these years I can easily spot them) enjoying the sights prior to running the race on Sunday. A couple of my meetings were held near Time Square, where sports demonstrations publicizing the Sochi Olympics were going on. It was a mob scene, but fun to watch.
I had no city meetings today, so I resumed my run schedule this morning. I’ve been running with my foot pod so that I can capture my cadence, but I still use the Garmin’s GPS to measure my mileage. Due to that, I haven’t bothered to calibrate the foot pod for distance. When I fire up the Garmin, it detects the foot pod and asks whether I’m running indoors. If I say yes, it will turn off the GPS radio and use the foot pod for measurement instead.
Today I went through the routine and when it looked like the signal had locked in, I was on my way. I hadn’t gone half a mile before the Garmin chirped saying I’d reached my first mile. I figured that the GPS signal must not have actually acquired before I started and the watch was working off the (uncalibrated) foot pod. I didn’t care much, because I always Gmap my run to get exact distance.
The watch did switch to GPS mode shortly after that, and my remaining splits were in line with my normal pacing. While I would have liked to meet the performance that the Garmin recorded for today’s run, I must admit to a far less impressive pace in the mid-9:00 range. So the Garmin lied, but I’ll forgive it. If I could run five minute first miles for real, I might actually break an 8:00 pace on my training runs.
One of these routes is not like the other
|Post run relaxing|
Today’s run (street): 3.36 or 3.41 miles
It was another mid-high intensity run this morning. My heart rate (the only performance metric I’ll view while on a run) was close to target, and I knew I’d be happy with my finish time. A quick look at the Garmin confirmed that I’d managed another good run. I cooled down by the pool when I finished and tried mapping my route using the Gmaps web app on my phone
I was pleased to see that the Android OS was finally supporting Gmap’s functionality. That allowed me to record my distance and calculate my true pace. I liked what I saw: 9:05. Although I worked for it, getting there didn’t feel as hard as I thought it would be. Looking a gift horse in the mouth, I mapped the run on my laptop after I’d finish showering and discovered a surprising disparity in distance.
|Distance: Android version|
|Web version, same route|
For some reason, the route on my laptop registered 5/100ths of a mile shorter than the exact same map on my phone. Weird and disappointing, because that small disparity meant my average pace was actually 9:12. Not bad, but not what I wanted to see. I remapped the route to see if I’d somehow missed a street, but the distance came up the same each time.
So what if the phone mapping is actually the correct measurement? That would be nice. But I use the web version as the standard, so I’ll have to go with that. In the end, the difference is measurement is minimal. Unfortunately, the difference in pace is not.
My Garmin speaks the ugly truth
|It’s a match|
Today’s run (street): 3.25 miles
I’m incredibly annoyed with my Garmin today. I did this morning’s run and, as always, recorded my distance using GPS. I always assume the watch will under-count my distance, so I wasn’t upset to see the indicated time and pace. Usually, after Gmapping my route, I’ll need to add about 3% more mileage to the calculation. That often makes the difference between a good and mediocre pace. Today, both the Garmin and Gmaps said exactly the same thing, and what they said wasn’t good. I missed my targeted pace by 23 seconds per mile.
There’s no reason why I ran this slowly today. I’d tried to focus on form and turnover. The weather was perfect, so heat and humidity were not a factor. Perceived effort was on par with my better runs and I even ran the last quarter in a semi-sprint. But in the end, my performance did not match up to expectations. Tomorrow is my last run before Sunday’s race, so I need to make it count.
|Zeotrope concept (left), example (right)|
I took most of the day to be with the family and we spent it at the Museum of the Moving Image in Astoria, Queens. The experience was great, and I even got to play with a nineteenth century zeotrope of a man running. But instead of marveling at this 100 year old wonder of technology, I was watching his form and thinking how he should shorten his stride.
Rethinking GPS versus foot pod
Today’s run (treadmill): 2.5 miles
My first method of capturing running data was with the Nike+ chip that fit into a concave spot located under my shoe’s sock liner. The accuracy of the this system was surprisingly high, but the software was buggy and the wristband that displayed metrics like pace, time and distance had serious corrosion issues. After going through three of these wristbands in less than a year, I got my money back and bought a Garmin FR50.
I had an amusing experience on the treadmill with the FR210 this morning. I wore the watch to capture my heart rate but, even indoors, it had locked in on satellite. When I finished my run I saw that the watch had recorded my distance at .14 miles. I’ve been considering using the FR60 again with the foot pod for treadmill runs. But for outdoor runs, I have to say the one big advantage of using the GPS watch is that there’s no fussing with calibration or switching foot pods. Nothing’s perfect, but at least I have a choice.
The declining accuracy of my Garmin FR210
|I’d add 3% just to be safe|
Today’s run (street): 2.53 miles (Gmaps measured)
I’m not sure why, but my Garmin FR 210 has been under-performing lately. It was especially bad this morning. I generally run the same route every day at 4:00 AM and, after careful measurement, I know that the distance is exactly 2.53 miles. The Garmin’s margin of error is generally -3%, which means that it under-counts to that degree fairly consistently. Since it is consistant, I accept that variance and correct for it in my pace calculation.
It’s no mystery why this happens. Looking at my run captured in Garmin Connect, I can see that the watch will vectorize corners and straighten out curves. This is due to the capture time between GPS signals (approximately one sample per second). If the signal was captured continuously, the course would be displayed accurately, with no corners cut, etc. When it’s cloudy, the signal can get interrupted. When that happens, the watch interpolates the distance between signals as a straight line. Enough of those and your accuracy really suffers.
Lately my FR210 has been under-reporting by about 5% and this morning it came in at -7%. It was cloudy, but clear enough to see some stars. My run could only be described as slow, and with the under-counted distance, my watch recorded my pace as glacial. Correcting for the true distance, it was still the slowest 4:00 AM run in memory.
I’m puzzled as to why my Garmin’s GPS has become less accurate of late. Perhaps it’s just going through a bad spell. The GPS accuracy tends to be better when I run a mostly straight course like at Bethpage. I’ll see how it does tomorrow.
In treadmill I trust. Or do I?
Today’s run (treadmill): 25 minutes
|This is the key|
A rainy morning kept me inside today so I did yet another treadmill run. I’m curious to know how close the readout on the treadmill’s display matches my actual progress and performance. I replaced the treadmill’s console a few months ago but wasn’t able to run the calibration sequence when I installed it. Every time I run on the machine I question the accuracy of its recorded distance and speed.
I’ve often felt that running on this treadmill (a Sole F63) and our prior Pro-Form unit felt harder at a given speed than when running on the road. A 9:00 pace on the Sole feels like about 8:50 on pavement. It may be that the treadmill forces a shorter stride and higher cadence that feels more challenging. I would think that the treadmill would feel easier and street running because there’s no wind resistance. Plus, you don’t experience hills unless you select an incline.
I still have my foot pod that links to my Garmin and I could probably answer my accuracy questions by comparing the Garmin performance with the Sole’s on the same run. Before I do that, I need to replace the foot pod battery and do some calibration runs outside in order to establish an accurate baseline. The other issue is that the foot pod won’t attach easily to my Hattori’s so I’ll need to run in a different shoe. I guess I can make excuses why it will be hard to test or I can just go ahead and try it.
News flash – GPS watches aren’t accurate
|Graphic from 12/19 NY Times article
Photo credit: Martin Strauss, via Garmin and Microsoft
Today’s run (street): 2.5 miles
There was an article in Tuesday’s New York Times about the accuracy (or should I say, inaccuracy?) of GPS watches. The writer made the same point that I’ve been making for years, that GPS technology does not provide exact measurement. The same can be said for smartphone GPS apps that show lots of metrics and graphics, but also under-count distance. The thing is, if your distance is off, so is everything else, including pace.
I’m a bit of a belt and suspenders guy when it comes to tracking my runs. I use a Garmin FR210 GPS watch to capture my run metrics and route. But later, I usually measure where I had run using Gmaps to get the most accurate distance. This way I can calculate my true pace. Why use the Garmin if I know it’s inaccurate? Good question. But just try taking my Garmin away from me…
This morning I got back outside for my early run and was rewarded with dry roads and mild temperatures. There was wind coming from the north that, when traveling head-on, made things chilly. Most of my route went either south or east so it wasn’t a problem. I managed an average pace, though my PE (perceived effort) was higher than that result. Then again, when you get your performance information from a GPS watch, you never know what to believe!