Is a daily marathon an 'Ultramarathon'?

Take a look at this website for "Running around Australia for Charity"



My aspiration to do a single ultra looks pretty tame by comparison!

Summer is here!

After a little disappointment earlier in the week today I was pleased to manage 15km, albeit at a very sedate pace. I easily reached Oxstones without complaint from The Knee but on the descent towards home it started to tense in the hamstrings passing behind it. That seems to be the recurrent issue now. After a bit of stretching (and making an attempt not to grip the ground with my toes) I was able to get back comfortably.

The panorama above Lady Canning plantation including Oxstones

Summer has arrived now, last week in Norfolk was hot and now it's back and forecast to last all week. Too hot for record speeds regardless of knees.

So this week has been 11.4km, 4.5km and 15.5km; that's progress.

Not quite there

Last week I've upped the mileage a little on the physio's recommendation as things had been fine .I did three runs of 9.4km, 4.1km and 7.9km and these felt relatively easy with a noticeable improvement in pace. Whilst away on a camping weekend I also did a 24km walk which whilst fairly level, involved a high proportion of cambered stoney beach. I felt that!

A sizable branch had fallen from a tree, blocking the path

With last week's positive progress I had planned to run 13km this evening but at 6km I was aware of a few twinges from The Knee and so turned for home. Still, 11km achieved without pain so that is a positive step.

Holux M1000C inaccuracy

This table shows comparative features of GPS loggers and notes that the Holux is low resolution. Could that explain the disappointing log data?

I've collated this example of performance to illustrate my concern. The lack of alignment of the Holux is not due to the Google photo as I've overlayed the GPX on both OS and OSM mapping on different platforms with the same result.

Three GPS logging devices and their respective tracks along a suburban track near home. Mapping is OSM, Google Earth and OS 1:25000 respectively. Software was Garmin Connect, GPS Visualizer and Android Viewranger. 

Holux binary logs record latitude and longitude as 4 byte,  32 bit floats. This should allow 7 to 9 significant figures of a decimal number which is plenty for real world logging.  It is also worth seeing this illustration of truncation errors.

5 minutes of capturing NMEA sentences followed by logging. Plotted as divergence in degrees from the average position indicted from each recording.

I have compared the standard NMEA data against the float32 capture data; the quantization of the latter is very evident. However note that the errors of both fall within 0.0001 degree for nearly all of the time.

A 0.0001 degree ring around a point in the outdoor swimming pool at Hathersage. Most points would be well within this margin.

This Google Map shows that this variation is little more than the width of a road and so the 'theoretical resolution problem' does not account for the real-world logging errors seen.

Out of the woods?

Yesterday I saw the physio again and she thought I could try a 'long run' today. The pain has become little more than discomfort and isn't really knee-related anymore. Just generally in my both legs! Anyway, I managed 9.2km which meant that I had run far enough to leave Ecclesall woods for the first time in a month.

A check of the Holux record showed it to be quite a long way off course again despite making an effort to leave the box exposed at the top of a bag with the battery on the lower surface. It's something to do with the location as the east of the woods has recorded more accurately than the west on 2 occasions now.

Knee recovering

The physio thought that this week would be a key test for how well I was recovering. Well so far it looks pretty good. I've run 1.8km, 3.8km, 7.0km on alternate days with no problems. Today I did feel a bit of tightness in my left hamstrings and that is a bit of an issue as it seems to upset The Knee.  Let's be glad of the success though.

On a down side, today was my first run with the Holux, comparing it with the Garmin 110. It was a damp day and the Holux was in a bag in a pocket and there was tree cover. It lost its signal quite badly resulting in some false recording of position and which increased distance covered and speed.

In this image the pink shows alignment of the routes, turquoise is Garmin and yellow is Holux. From the mapping data it is clear that the Garmin route is the most realistic. Perhaps this isn't the device but position, a wrist is far more open to the sky than a wet pocket. I'll have to test this. On the plus side, it has run for 15 hours on a single charge with Bluetooth enabled, and the low battery indicator is still off, so that's pretty good.

Holux M1000C on Android and OSX

Although the Garmin Forerunner 110 is a great training aid it's not reliable to log ultra runs as its battery life is only 5 to 6 hours in GPS mode. Ok, one doesn't do longer runs very often (indeed ones body can't cope with it) but it would be a shame not to log them. Additionally,  some events don't permit GPS aids, but you might still want to log the route. The answer is a display-free logger, such as the Holux M1000C, and similar devices.

The 'user interface' is very simple, an ON-OFF slide and 3 LEDs, amber, blue and a red/green one. This makes its use pretty foolproof and no one can accuse you of getting assistance from it! In the UK these retail for around £40 from online shops but they do seem cheaper (and dearer) elsewhere. One of the great things is that it has a removable mobile phone type battery so very long use times can be achieved without a socket.

It is supplied without software although some for Windows can be downloaded. However, despite what the manufacturers say, the loggeer will work well on OSX, Linux and Android as the chipset is commonplace and developers have made software to download the data and convert it to GPX files. I've been using Androidmtk so I can read the data via my Nexus 7 and upload from there.

It's worth mentioning that presently the programme muddles the <ele> and <speed> tags in the file as the Holux M1000C swaps the data in it binary file compared to other MTK-based devices. However this isn't a problem as most online GPS mapping services use an altitude map to define height rather than the (usually rather poor) GPS-derived altitude.

Also, the BT747 software on OSX seems good too as it will control the features of the Holux rather than just downloading. I had a bit of trouble getting the USB 'serial' port to be recognised and I ended up using the Silicon Labs USB to UART driver with a recent (ie non default version) of BT747 as there's some issue with the version of a module incorporated into the program:

On my computer (Snow Leopard on 64bit Intel) the correct 'USB' serial port to use is /dev/cu.usbmodem24310 but it could be different for you. My old iMac doesn't have Bluetooth, but that might be an easier route to go. I can't get any version of the software to work on a 6 year old 32bit Core Duo Snow Leopard MacBook with either USB or Bluetooth.