Five Fingers - a two weeks review

Why would you possible wear such strange looking shoes?

Those Vibram Five Finger shoes have caught my attention every now and then during the last years, but up to now I couldn't really get myself to give them a try. Due to my upcoming beach holidays and my recent interest in natural running, I finally got myself equipped with a pair of those. Due to the fact that it is hard to find a local store, which has a good coverage of the various Five Finger models - yep I was surprised as well, there are like 15 different flavors of those - I decided to order from their German online shop.

I selected to different models from the website: KMD Sport , KMD Sport LS and KSO. I hoped to use the shoes as leisure/beach shoe and for some - yet to be determined - extend also for running exercises.

Unboxing experience

At the day the parcel arrived, I first tried the KSO. Took me quite some time to get my feet - specifically my toes - into the shoes, but have been rewarded by a superb barefoot walking experience. Actually the KSO is almost not recognizable on the feet.

While it was a hazel to get myself into the KSO, it was close to impossible to get into the KMD models - at least the first time I tried. On the second try it took me still like 10 minutes the maneuver all my toes in the appropriate boxes.  Compared to the KSO, the KMD models are more recognizable on the feet. In direct comparison to the KSO, they feel almost heavy, but in comparison to normal shoes like nothing.

Which model to keep?

I spent like 3 days in which I spent my spare time in the flat with alternating between the different models and than finally decided to keep the KMD Sport LS model. While my initial love is with the KSO model - fantastic barefoot experience - I decided to go with a KMD model. Reasoning here is that I would think that this shoe would cover a broader spectrum of possible use. Specifically it should be more suited for running. I decided for the LS model with comes with laces as those gave me a better fit of the shoes.

Does it work?

Yes - During my 2 weeks of vacation a Usedom - German island in the Ostsee - I used to Five Fingers as my standard shoes. I drove the 600+ km car journey to the island still in my vans and didn't touched those for the entire two weeks of vacation. Beside the 5F, I only used running shoes for my running exercises.

The 5F are perfectly fine to walk to/on the beach (yes, you will have sand in the shoes just like in regular shoes) and standard walking activities in town, beach promenade and alike. I also have been wearing them for our casual family bike tours - no issues here. I would still prefer my click shoes for real biking.

I did quite some running exercises with the 5F on the beach and on asphalt. This works fine as well. I tried to hold down on speed and extend of those exercises, to provide my feet and legs some time to easily get used to the new shoes, but running on the beach in the sun was so much of good fun that I ended up with 14km run, which is probably not what you want to do during the first 2 weeks. Refer to "Natural Running" book from Danny Abshire.

Definitely even only walking in the shoes does put some stress on your feet and lower legs as they need to get used to this kind of shoes. In my case this got a little bit pushed in the background due the overall training stress I put to my body as I ramped up my training for the upcoming marathon.

During the two weeks I had issues with blisters, but those only appeared while I was either running in my standard running shoes or purely barefoot. I guess those are unrelated to the five fingers.

Not sure if this actually is a good idea, but I also wear the 5F on the car ride back at the end of vacation - nice direct control through the pedals ;).

What is the *AF?

Most importantly is obviously the WAF - specifically the opinion of my wife. She kind of concluded that those shoes are looking very strange but kind of fit to the overall way I dress/appear. I took this one as a GO.

The general acceptance of this kind of shoes is actually quite mixed. Although I only have been wearing those shoes in holiday/leisure situation, people do recognize those shoes. But to be honest, you can easily mitigate this by wearing an action cam mounted to your head :-).

I still need to figure out the BAF - Business acceptance factor. At the time of writing this, I'm on my way to the 1st office day, actually not wearing my five fingers. Mainly because they need to be cleaned, but to my feet, the plain old business vans feel awkward already ... I'm considering to possible buy an additional pair of black KSOs - as they provide just a pure feeling and are less exposed in the design. Still undecided.

What is next?

I'm looking forward to wear the 5F as much as possible as my standard shoes as they really provide a good walking experience. Furthermore I plan to have regular short& light training sessions with the 5F for the time being. As I prepare right now for the next marathon, I'm not able & willing to transit to a natural running style. This should be the aim after the marathon. In the meantime I'm still seeking for some good natural running shoes. I would aim for a pair of Newtons, but it seems to be pretty hard to get hold of them in Germany - and not really at the cheap end of the spectrum as well..

I'm looking to test the BAF tomorrow in the office - I'll keep you posted...

How do services like Runtastic refine elevation of my GPS tracks?

How Does elevation refinement work?

Recently I recorded a load of GPS tracks during my running workouts. Those tracks a recorded with a GPS watch and I tend to upload those tracks to a fitness service - specifically to runtastic.com - in order to review my runs, obtain statistics and share runs with my friends. Similar to other web services runtastic.com offers the functionality to refine the elevation of the track recorded. This makes sense as most of the times the track shows peaks and lows which cumulate to unrealistic altitude difference. So far so good - but how does this work?

My initial assumption - maybe driven by the fact that you can trigger  the elevation refinement next to the map plotting your run in runstatic.com - was,  that they would use the elevation information coming from the map provider to correct the elevation. So basically for each track point they would need to obtain the elevation information and correct the track. Quite some effort and since elevation API provider like Google enforce limits to the number of API calls you could make or charge for them, this might be too much effort.
Alternatively they could use some kind of filter (e.g. like outlined in http://blog.ridewithgps.com/blog/2012/04/19/April-2012-Ellevation-Data/). This would allow them to smoothen the elevation information without dependency to external knowledge.

So what is the truth? Hard to say as I couldn't find any information on this topic on runtastic.com. What now? Experiments - what else? If we could have GPS tracks which are not made on the ground (e.g. during walking/running on the ground), but above the ground, we should be able to figure out which approach has been taken. If it is map information based, those tracks should be refined to the ground, while a pure filter approach should just smoothen the elevation curve, but not map it to the ground.

Experiment #1: GPS track on the plane

So first idea is simple. If I can not run on the sky, I need to board a plane. Luckily I had the opportunity to track the launch of a flight from London Heathrow to Dusseldorf. Unfortunately the watch lost GPS signal after 150km, but this should be good enough for our purpose.

The screenshot below illustrates, how the track looks like without any elevation refinement being made.

As you can see, the track shows a quite smooth elevation curve, which actually shows to periods in time where the plane gained steadily height and finally a small adjusting to travel height, which is slightly above 5000m. So far so good. What happens if we ask runtastic.com to adjust the elevation? See screenshot below.

Whoa - I wouldn't have wanted to be in this flight. Two reasons: a) the former nice and smoothly curve is now showing a quite rough ride and b) the whole flight is shown to be below 150m.  So - without checking the geographic conditions - I would assume that the track has been mapped to ground height.

Let's do one more experiment...

Experiment #2: GPS track on a - presumably unknown - landmark

What else can we do? One of my favoured local running tracks goes up to a landmark called Tetraeder (http://de.wikipedia.org/wiki/Tetraeder_(Bottrop), sorry only German). 

The landmark is placed on a mine heap, which is about 90m higher than the surrounding are. The Tetraeder itself can be climbed up to an height of roughly 40m. What happens if we track a "run" on this one? First lets see the pure data (image below).

Elevation shows a more or less steady peak which consists on the way up to the mine heap and then climbing the stairs afterwards. So far so good - what happens if the refine elevation?

Ah ok - we lost the cap of the peak in the elevation chart. Looks like that runtastic.com uses some elevation data provide which is not aware of the landmark, which results in removing the height being gained on the stairs up to the landmark - and I can assure you that is was quite some effort to get up  there ... ;-).

Conclusion

Looks like that the initial assumption that runtastic.com is using some elevation data secondary to the GPS track being uploaded is correct. This would mean that you would struggle, if you are trying to use this service for e.g. managing your ultra aviation tracks, but this is no use case for me anyway. Wonder if I should upload this to http://uselessfacts.net/ ;-) Thanks for your patience...

Update:

I just found https://strava.zendesk.com/entries/20965883-Elevation-for-Your-Activity which explains how strava - another runtastic competitor  is dealing with elevation data. They consult elevation databases.

Another Update:

I just found another service - http://runalyze.de/ which looks promising. I didn't tested it yet, but you can use the online hosted version or run your own. Seems to be around for quite some time, not sure why I never came across it. I will give it a try. On the topic of elevation correction, they provide some insight in a blog post - http://runalyze.de/tutorials/hoehenmeter-korrektur-und-berechnungen/ (German only).