Life is an ultramarathon

With such a name, these shoes can only be good (although there are also the "Salomon XA Pro 3D Ultra GTX", which must be amazing) :) . I bought these trail running shoes on Saturday and tried them straight away on a 29km run the next day. That might not have been a brilliant idea, as I came back with a massive blister under my left arch. I hope this is only a first-use issue... I needed something intermediate between my road running shoes and the Flyroc in order to replace my beloved Asics Gel Orient that carried me on 3 UTMB. The Flyroc are a bit too hard on the concrete (and get worn out pretty quickly on hard surfaces). The Salomon XA Pro 3D Ultra is a classic trail running shoe, pretty lightweight, without too much cushioning. As for the grip, it's not too bad on wet grass (although I was expecting a bit better), but not so good in deep mud. I can now wear the following:

• New Balance M1062 for the road and hard paths (next: Vienna Marathon)
• Salomon XA Pro 3D Ultra for the easy trails (next: Cambridge Boundary Run)
• Inov8 Flyroc for the mud, technical trails and off-path (next: Hardmoors55)
• Vibram Five Fingers for the fun

Obviously, with experience and practice you can still fly downhill without the need of a massive grip, but it nevertheless makes things easier when you're tired.

Ultra Salomon XA Pro 3D

Last week-end, I carried on further tests with the VFF (see part 1 and part 2 for introduction and previous tests).

Trial 6: Canoeing
On Saturday I went canoeing on the Wey River around Farncombe, Surrey (between Guildford and Godalming). I think this is one of the activity at which the VFF perform very well. They've got enough grip to handle wet surfaces and obviously you're not afraid to get them wet. Which means that you feel more free to mess around, jumping from one boat to another or to trees, walk in the water, climb ropes hanging around, ... Nothing to do with barefooting and gait correction, but comfortable and very good fun!

Trial 7: Climbing on sandstone
On Sunday I went climbing at Harrison's Rocks. I originally brought the VFF for approach walks as they're well suited for trail walking and are very light, which means less burden when clipped on the harness during climbing. But at some point I decided to try them on relatively easy routes. Because of their weak arch support (to say the least), they're not suited for edging and as discussed earlier, their grip is not worth my climbing shoes'. On sandstone however, where the grip is poor anyway and smearing is fundamental, they are actually usable for easy-ish warm up routes. Because they're more flexible (and comfortable) than conventional climbing shoes, they sometimes allow to push into the rock with a more optimal angle, counter-balancing their weaker grip.

Ultra thin soles 3

After a long period of indecision, I've eventually decided to buy a pair of Vibram Five Fingers shoes (sprint model). I guess they can be best described as a pair of gloves for the feet.

I've been attracted by them for several reasons, so many that I actually feel like I've been naively caught into excessive consumerism by some clever marketing teams :)

1. Novelty factor and the satisfaction to try something singularly different.
2. Sensations, following the idea I've developed in "The tortoise and the hare" about seeing every single meter of ground between London and Brighton, I hope to additionally be able to "feel" every meter of ground. It is not clear yet whether I'll be able to run long distances with them or not, but the principle applies to shorter runs too. Gaining extra feeling on the feet will hopefully contributes to this idea in two ways. On a physical level, I hope they will provide an extra source of sensation, just as the Inov8 Flyrock were surprisingly a lot of fun to run with on slightly adverse terrain (sand, mud, snow, ...). On a more psychological level, they might help with the "connection with the Earth" type of feeling.
3. Injury prevention: there is increasing evidence that modern, massively cushioned running shoes are not necessarily better than their cheaper counterparts, with studies showing that people running in expensive shoes are more that twice as likely to get injured. Cushioning gives the human body the impression that it can land heavily, which inevitably alters the walking/running style way. Whether this is problematic or not is still up for debate amongst sport scientists. Beside, several studies have shown that induced stress on the bones triggers bone growth, which will later delay osteporosis. Now, where is the limit between beneficial stress and harmful shocks is not clear. But after all, the human body was originally designed to walk and run barefoot.

I guess I can only try them in various conditions and see whether they meet my expectations.

Trial 1: shopping at the local supermarket
The first thing I noticed when I went out was that I could very easily tell apart the different kinds of concrete and asphalt I was walking on, which is rather nice. The second thing is that the impact on the heel and on the metatarsals feels fairly hard compared to using typically cushioned shoes. And the third thing is that you don't walk unnoticed - lots of people literally scrutinised them. Some people say they look silly. That said, millions of people have bought the Crocs which look ugly even to my underdeveloped sense of fashion. Personally, I think the Five Fingers look rather funny.

Trial 2: commuting walk
I then decided to walk 5km in them to see how they feel on longer distances. Again, the heel contact is rather hard, unless you try to land mid-foot or even on the toes. However, I couldn't sustain that for very long as I not only looked like I was training for a catwalk, but it's also fairly hard to balance on landing. Towards the end, I started to get blisters under my heels, which is fairly unexpected. Furthermore, I took a couple minutes longer than my usual commuting time, which can be impeded on the shorter stride required to reduce the ground reaction force during the initial heel contact. Walking a bit on the grass in Hyde Park felt so much better than the concrete. I guess humans were designed before the roads.

Trial 3: short run in the park
I then went for a 6.3km short run in the park. At first it felt pretty good, as it's much easier to land mid-foot or on the toes while running than walking. Soon, I managed to bounce on my arches, with my heel barely touching the ground, as if my feet were mounted on springs. That led to a great feeling, just like I was moving effortlessly. The concrete felt rather hard, the grass was nice, and the sand (for the horses) was great. Little by little, though, I started to feel the tiredness in my arches, and when I eventually stopped I thought my calves would seize up - they didn't.

The outcome of these preliminary tests is rather positive, but I don't think I will suddenly change completely my habits and drop all my other shoes for this new pair. I will just gradually replace some (short) training sessions or commuting walks. That should help to strengthen some muscles of the lower legs and feet. And that will diversify even more my running and walking habits, which in my opinion is the best way to prevent injuries. Indeed, variety in running session characteristics such as distance, speed and surface reduces the risk of injuries.

Further tests are to come: hill walking, trail running and maybe climbing, open water swimming and canoeing. I guess they might be more suitable for these activities that do not take place on concrete, although it's hard to guess what their grip will be on wet/muddy terrain.

> Tests continue in part 2 and part 3.

Ultra thin soles

PS: Note that the brand name "Vibram" has nothing to do with anti-vibration insoles as I've heard sometimes. It's derived from the company founder's name, Vitale Bramani.

Most people strongly recommend the use of profile bars. A minority, however, say they're useless unless you're an elite cyclist (aerodynamic considerations indeed become more important with higher speed) and argue people only mount them on their bike as a statement - "I'm a triathlete".

In the quest to tune my bike into a more efficient, triathlon-like machine, I've therefore tried to adapt profile bars. I finally gave up with the Oval A710 previously installed, as they were too uncomfortable for my arms. I recently replaced them with the Profile Jammer GT, apparently more suitable for long rides. They're higher and feel better in the arms. But I don't really have a good feeling with them: it feels like my lower back is supporting most of my upper body weight (when my forearms should help) and I can't drive as much power from my legs. I have a feeling it's because I have relatively long legs and the bike frame is fitted for that. Thus, the handle bars are a relatively a long reach, and the profile bars worsen that effect. The good point if this hypothesis holds is: I'm low enough on the bike and don't really need profile bars. That would make my bike lighter. So profile bars or not? I may try to take pictures of my riding posture to take a decision.

Ultra aerodynamic decision to make.

Just as with the Nike + iPod, I got the chance to try out a Polar RS800sd bought for the lab.

It consists of 3 main elements:

• An ECG belt to get the heart rate through comfy textile electrodes.
• A foot pod, measuring stride length and cadence, based on inertial sensors (accelerometer and maybe gyroscope).
• The watch gathering wirelessly the information from the two above and connecting to a PC.

I went running in the park for 6.33km, again without pre-calibration. The watch told me 6.43km, not bad! Only 1.6% error, to be compared with 33% for the iPod gadget... Technically, the main difference between these two apparently similar systems is the foot sensor. The iPod+Nike relies simply on a contact sensor that can't do much more than counting your steps. Therefore sensor calibration is crucial. I wouldn't mind calibrating the sensor once, but every pace change means recalibration! I guess Nike has never heard about interval training and that sort of things.
To test the limits of the Polar, I tried it walking instead of running, and it behaved very well, as I got a very similar error: 1.6% above. I guess I just need to calibrate it once to get near-perfect distance/speed estimation at any pace. I finally performed an ultimate test on the sensor: I ran on a treadmill :) . This tricked the sensor. Indeed, your actual speed is null, whereas your feet are moving. It displayed a 13km/h running speed when the treadmill was set on 15km/h (13.6% off).

You can use their software (PolarProTrainer) to upload your data, view the training calendar, running curves (speed, heart rate, cadence, altitude, ...), evaluate your training efficiency, and even program some exercices to be sent back to the watch. It seems to have loads of functionalities, but the look and feel is not great.

Some Adidas shoes have a placeholder for the sensor (just like the Nike for the iPod one). Better: some Adidas shirts have embeded ECG electrodes for a truly wearable sensing.

On the whole, the iPod+Nike is just a fashion gadget based on the Apple hype, whereas the Polar system (with or without Adidas) is really designed for training. And I swear I'm not paid to write that!

Ultra running sensor.

I've been thinking for a while about a system to broadcast the runners GPS positions live during a race. Nowadays, things are getting more and more simple for three main reasons: the integration of GPS in mobile phones or the easy connection via BlueTooth, the possibility to program mobile/satellite phones, and the simplicity to broadcast positions over the internet via tools such as GoogleEarth. There is no need for a PDA to link the GPS receiver and the mobile phone anymore.
On races such as the UTMB (r), mobile phones will be out of coverage. Therefore satellite phones seem to be the key. Most of them include a GPS as well (*), and embed a decent operating system. I was thinking to buy a cheap second hand satellite phone for that purpose, but they don't seem so cheap :-/ Even more expensive on ebay than through regular retailers... The other issue is to write the application that will get the GPS position every 15 minutes and send it though the satellite link via SMS or HTTP, the latter being easier if available. In order to use all the specific functionalities of the phone, a SDK is probably necessary. I've not found any for Thuraya phones for example.

Can anyone help me with one of these two points: where to find a cheap satellite phone and how to develop on it ?

Ultra tracking.

(*) this is not as obvious as it may seem, as satellite phones and GPS devices use different kinds of satellites and technologies.

This morning I had the chance to try the Nike + iPod "Sport Kit". Not that I would buy one, but there's one in the lab for wireless body sensors testing. It's basically a wireless bluetooth-like accelerometer you fit in (on) your shoe and a receiver plugged in the iPod. A quick look on the internet before going for my run and I found the blog of an iPod aficionados. He successfully used the sensor with non-Nike shoes and without pre-calibration but managed to get a pretty good accuracy (about 1% to 2% error).

I then confidently ran 2 loops in Hyde Park. The distance is about 6.3km, measured on several maps, with several tools (ruler, curvimeter) and on GoogleEarth by several persons:


After my run, the iPod displayed (*):


Hmmm, it reads 8.53km, when I expected ... 12.66km (2*6.33) ! That's an amazing 33% error ! One of my colleague faced a similar error. Even more worrying: some also reported a wrong recorded time. Of course, I didn't calibrated it and I didn't use the Nike shoes. But well ... that's just as good as a good old mechanical podometer. I guess they don't do anything more clever than counting the steps. I believe that with a Walkman, a podometer, a watch and a couple of transistors something more functional could have been designed 20 years ago ...

Our aficionados must be very naive (or well paid) to be "very thankful that Nike and Apple made it possible to use it with alternative running shoes" ... Not only you have to buy the gadget anyway, but as it's not very convenient to wear, you'll probably buy some compatible Nike shoes next time.

Ultra Christmas gadget.

(*) yes, date is not set properly

EDIT (18/01/2008): this is actually not an accelerometer, but a simple contact sensor. Therefore it can only count your steps - this is a basic podometer... See Sparkfun for example.