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).

Official Google Blog: Supercharging Android: Google to Acquire Motorola Mobility

Official Google Blog: Supercharging Android: Google to Acquire Motorola Mobility

All about Dynamic Views for Authors - Blogger Help

Just played with the new Dynamic Views feature on Blogger (All about Dynamic Views for Authors - Blogger Help). I really like the timeline view. Cool shit. BTW this is my first post utilizing the Blogger extension for chrome - so less a content -heavy post but more a test ;-)

Slackline Project - Ground Anchors

This post is a follow up on my earlier posts Slackline Project - Requirements & Feasibility and Building A-Frames . You might have a look there to get the context.

Disclaimer: This goes on top of the standard disclaimer. I'm neither a experienced slackliner nor some sort of construction engineer. So if you want to utilize some information from below: Just do it but your should crosscheck the information with some experts before you apply it! No guarantees from my side.

The A-Frames are providing the height of the slackline, but still we need some fixpoint to attach the line to.  Slackline set desigend for A-Frame using ground anchors like Slackline-Tools Groundanchor or Gibbon Slackline - Ground Anchor which create a fixpoint by screwing the anchor into the ground. That is pretty neat as it is easy to be done and you can easily remove the anchor afterwards. At the same time it is pretty expensive.

During the search for alternatives, I found that e.g. kids swings are commonly attached to the ground with the same kind of anchors (e.g. http://www.spielplatz-shop.de/product_info.php?info=p40691_Bodenanker--Erdanker-im-Paar.html). Those are way cheaper but differ at least in three points from the slackline- anchors:

• The length of the anchor is shorter. Therefore the anchor would go less deep into the ground and hence hold less. I found statements like if you dig the anchor 20cm below the ground level, you could double the strength of the anchor. Not sure if this is correct, but it makes sense that the length is important.
• The screw diameter is lower.
• The eye is not closed and might therefore hold less.

For sure there are also more differences in material and such, but finally I decided to go with http://www.fassadengruen.de/uw/rankhilfen/uw/artikel/ea12800/ea12800_erdanker_bodenanker.htm?no_cache=1&sword_list[0]=anker. They offer anchors with 80 cm length and screw diameter of 12 cm. I'm using two of them for each end to get some extra security. That is not much of a problem as I don't intend to remove the anchors frequently. All together way cheaper than buying a pair of slackline anchors.

Some first tests show that this seams to work. I could build up the line and use it a couple of times already without indicating any issues. It is quite important that you have some massive bar at hand to be able to screw the anchors into the ground. Without it is a hard to get them in to the ground. Out of curiosity I removed on of the anchors from the ground. It wasn't really easy to just screw it out, but I needed to dig it out partly. Leaves pain in the back and a more secure feeling ...

Note that not each kind of ground is equally good to places such anchors.

Finally we need to select a line and some more connection parts to get everything together - that is going to happen in the next post.

Slackline Project - Implementation - Building A-Frames

This post is a follow up on my earlier post Slackline Project - Requirements & Feasibility. You might have a look there.

Disclaimer: This goes on top of the standard disclaimer. I'm neither a experienced slackliner nor some sort of construction engineer. So if you want to utilize some information from below: Just do it but your should crosscheck the information with some experts before you apply it! No guarantees from my side.

Looking at the low budget requirement, I decided to build my own frames rather to spend something like 50 - 90 EUR each. As I mentioned in my last post already: The web is full of self- and professional build a-frames. Should be possible to build something by my own. So I went into the garage to inspect the pile of left-over wood boards and found a former kitchen work disc (170 cm x 60 cm x 3 cm) made from massive beechwood. 

From that I obtained two frames- roughly 80 cm high and support three different slackline heights (30, 50 and 75 cm). The basic design is depicted below.

I was not sure about the proper heights. I might want to add a fourth one between 50 and 75 cm at a later point of time. To be honest - I asked some friend to saw the frames as I don't have the proper tooling at home, but that shouldn't be to much of a problem if you are somehow a  do-it-yourselfer.

That's how the frames look like after being glazed to be protected from the weather impact:

So that are my frames. I guess the low budget requirement wouldn't be fulfilled if I couldn't reuse the work disc for this purpose. In this case it might be a better idea to go for a design which goes with less amount of wood ( video linked from my earlier post.)

In the next post, I will talk about the fix points I have chosen to hold the line.

The Slackline Project - Requirements & Feasibility

This is all about slacklining - the ability to do it in the own garden. Is it real project - certainly not, but sometimes it is good fun to bloat something up.
We got in touch with slacklining while we spent some time in a climbing hall. Its good fun to exercise your balance while you rest between climbing routes. There a people who bring it a couple of levels ahead like video - slackliner.at - that's certainly not what we are looking for - or ?!

Disclaimer: This goes on top of the standard disclaimer. I'm neither a experienced slackliner nor some sort of construction engineer. So if you want to utilize some information from below: Just do it but your should crosscheck the information with some experts before you apply it! No guarantees from my side.


Usually you fix your slackline just between two strong enough trees and you are done. Unfortunately our garden looks like this:

Quite some strong enough trees - but all planted in one single line with barely enough distance in between. That wan't be easy, but luckily we are the first ones to face this issue - there are solutions out there. So let's have a look on the requirements we have and then explore the solution space afterwards.

1. Modifiability: The whole place is rented. From that perspective the construction should have minimal impact and should be reversible once we are leaving the place
2. Low Budget: The whole thing is just a fun project and might enqueue itself into the things we started but never really took up. So the budget should be minimal to this one.
3. Reliability: It is intended to be used by kids as well. So it should better not break and put us in risk to be hurt.
4. Flexibility: It needs to be adjustable to different heights and lengths to support different user groups and different skill levels. We don't intend to move the setup out of the garden necessary.
5. Inconspicuousness: The setup shouldn't dominate the whole garden. Mind the WAF.
6. Time to Market: The whole thing should be done in a couple of days to be able to use it in the upcoming spring already.

So that quite some requirements. Note that the order does not necessary reflect the priority of those. So let's explores possible solutions and there feasibility.

Solution 1 : Use the existing trees

Solution is depicted below. 

Wouldn't be big fun and does not support the requirements for flexibility (only quite short distances are possible) and inconspicuousness (plants between the trees would certainly be impacted).

So this is not a Solution.

Solution 2: Plant new trees

Again the solution is depicted below. 

Would be nice and has the big advantage that it supports the standard slackline setup - no fancy special stuff needed. However it does not necessary fulfills the modifiability requirement (not sure if the landlord would be happy to find a new tree in the middle of the garden) and really TTM is going to be a problem - certainly we would miss a couples of seasons. 

So this is not a Solution either.

Solution 3: Use the garage as additional fixpoint

This solution utilizes the garage wall/corner as one fix point for the line. As a second one of the existing walls is used. 

Browsing through the - at least German speaking part - of the internet, you find quite a lot of discussions how to implement such a setup. Looks like you would need to drill through the wall and fix a plate on the opposite side of the wall to guarantee the required resistance. Note that the line impacts the fix-points with quite some force (you find numbers which are easily reach the equivalent of 1000 kg / not that easy to calculate). Certainly you need some good understanding of the statics of your garage to build up such a solution. From that perspective it is a hard to implement this solution. Furthermore, it does not support the modifiability requirement. Sure the landlord wouldn't be to happy to find such a thing drilled to his garage(not talking about a collapsed wall in case it goes wrong ;-)). Finally the flexibility is not to good (only one height) and Inconspicuousness is also not supported as it would cross the whole garden. So, that is also not the Solution.

Solution 4 : Use ground anchors / frames

This solution does not require any trees or building to build up a slackline. It utilizes fix points at ground level and creates the height of the slackline by using frames. The frames are typically formed in a letter A shape. The solution is depicted below.

Mostly you find a-frames constructed from wood. The fix point are either established by some strong nails or specific ground anchors. You can find quite some information to build your own a-frames in the internet (e.g. Build a slackline frame ). Ground anchors specifically for slacklines are available by some brands but there are also other ground anchors (e.g. for fixing kids swing frames). There are also neat sets available like the Gibbon Independence Set or Slackline Tools - Frame Set. Overall this solution could fulfill all of the requirements above. Some of the available sets are offering quite a nice flexibility - even more than we actually need as we don't intend to move the set around. Problem might be the budget. Building frames and possible select cheaper anchors could help to reduce the cost, but will impact TTM and possible reliability.

Putting everything together - solution 4 is the most attractive solution. I will explore the do it yourself variant a little bit more closely and keep you posted on this.