My articles about running, cycling, and the lessons learned from pushing physical and mental limits.
Yesterday I finished the Leiden Marathon, it was the hardest 42K I ever completed due to the temperature. Sunny with a clear sky, temperatures climbed to 25°C. Several runners collapsed from heat exhaustion, and one even required resuscitation. When you push your limits, sometimes you actually reach them. Here are a few thoughts from the experience.
While running my rounds around the village, it struck me that I could use ThreeJS to craft a dynamic 3D representation of my workout data. Read along to see what I’ve created—it’s a work in progress but serves as an exciting exploration of the concept.
Gran Fondo, the app that tracks runs and rides, is going open-source. I’m removing its subscription model and make it libre. This isn’t about short-term revenue—it’s about building something enduring, private, and free for all. Here’s why I’m taking this plunge and what’s next.
Earlier this month I ran the Valencia Marathon (42KM), just six weeks after finishing my first ever marathon in Amsterdam. I used two different approaches for these races: running on feeling and running on data. The experience differed greatly, let me explain it in this blog post.
Last Sunday I completed my first full marathon, covering a distance of 42KM in and around Amsterdam. An idea that started in a bar with some beers and concluded with a finish in the Olympic Stadium. What a journey, what an experience, well worthy of a blog post.
As a little side-project, squeezed between my normal work, I have been working on something of personal interest: a native workout tracking app for iOS. I wanted to make my smartwatch obsolete, instead using my phone to track workouts. How hard could it be to gather detailed sensor data using native Swift APIs?
Last Sunday, I participated in the Venloop, a half marathon event in Venlo. I completed the 21KM run in 2h05, a result I am satisfied with as this was my first ever 'official' event since I began running just three months ago. In this post, I'll share my experiences with training, balancing fitness data, and feeling fit.
Since the start of this new year I am working out harder than the previous months. I have set some goals for myself and have taken on a training scheme incorporating running, cycling and swimming. As I sift through the growing mountain of workout data, I find myself questioning: does having more data truly translate to better fitness outcomes?
The darker days are here in the northern hemisphere, and so is the need for good lights on your bike. Although battery powered lights can do the job, you need to keep them charged. I wanted a light system on my road bike that just works. Read along for some light in the darkness!
It's been over half a year since I moved from the city to the countryside. I regularly travel between these locations for work and leisure. Being a cycling enthusiast, I keep a bike at both places, and this has led me to discover a funny thing.
This Monday I completed 235KM on my fixed gear bike during the Fietselfstedentocht 2023. It was a nice ride with fair weather and favourable wind conditions. Yet, I took the challenge seriously and prepared myself with some proper training. In this post I'll have a look at the trend data from my WHOOP in preparation for the Elfstedentocht.
In preparation for this year’s Fietselfstedentocht (236KM), I took my bike and set out for an adventurous ride through half of the Netherlands. It was my first long distance ride after being infected with COVID. If you're considering a long-distance ride yourself, be sure to read along to discover invaluable tips and tricks from my experience.
Rarely have I been so amazed by a bike: the past 5 months since I've picked up my Brompton foldable bike in Amsterdam have been great fun! About 500KM down the road, I'm happy to share some of my experiences with this ingenious piece of engineering, read on!
This morning I enjoyed my bike ride on a nearly empty bicycle lane, picture perfect rays of sunlight illuminated the dew above the fields around me. Where were all the other cyclists? I suspect it has something to do with popular weather apps. It strikes me how great the control of computers on people's lives already is.
How often do you look in the mirror? Probably more than a few times a week! I have been thinking about this ever since I received my newest WHOOP 4.0 biometric sensor. It's great. But, why do I wear it? What value does it provide? Why should you wear it?
You might wonder how puncture proof a "puncture-proof" bicycle tire really is. I set out to find the answer when I installed Schwalbe Durano Plus tires on my bike. It was inevitable for me to find the answer to the question: How many kilometers can you ride without flats using puncture-proof tires?
Today I took my fixed gear bike for a ride, 176KM from Amsterdam to America (Limburg, The Netherlands). Rain and wind added to the challenge, creating an ultimate test for man and machine. Let some of my fun be of inspiration to you!
This week my trustworthy commuter bike started making strange squeaking noises when braking. It has been just over three years since I started cycling on it. People frequently ask me how the bike is performing and how the Gates Carbon CDX belt drive is doing? Time to have a look at the bike after 21.000KM!
Last week my son and I where looking for bears in the local park... a child's fantasy is priceless! Unfortunately, during some off road riding with our cargo bike, one of the cables got tangled up with a sturdy branch! Our wounded carbo bike was in need for a repair!
For the past week I have been riding my bicycle with Omata One, a special bike computer. Its mechanical hands indicate speed, distance, ascent and time ridden measured using precise GPS data. It is fun, read along to know why.
This month my trustworthy Giro Aeon bicycle helmet broke down! Normally I wouldn't hesitate to invest in safety and thus buying a new one. But I like the Aeon helmet so much that I went through some extra trouble to fix it. Read along to see how I did it.
For the past few months I have been riding a special kind of bike, the minimalistic Siegfried Road from Schindelhauer. It is unlike most road bikes as it lacks a conventional chain and derailleur. It features the Gates CDX carbon drive. It's an exercise in minimal design. After riding it for nearly 1000KM, it's time to tell you all about it.
The past months I have been wearing the WHOOP Strap 3.0, a wearable sensor that collects health and fitness data. It's different compared to most other fitness bands as it was designed with professional athletes in mind. It is focussed on daily strain, recovery and sleep. Read along to find out how this works.
Earlier this month my dynamo powered headlight on my commuter bike needed replacing. One of the electrical connectors broke of, likely caused by intense daily use. I searched for the best possible light, one that would be extremely durable and bright. I found the Supernova E3 PRO 2 and decided to install it on my bike.
After I created a minimal road bike, I decided to install a power meter to find out what's it like to measure the power output of my legs. What can you learn from a power meter? Is it difficult to install? Is it worth it? Read along to find out.
Over the past months I have worked on different bikes, leading to an accumulation of spare parts in my garage. I wondered how hard it would be to make a new bike using these spare parts. I decided to take advantage of this moment to refinish some parts, removing excessive decals in order to create a minimal looking road bike.
With modern wearables, smartwatches and fitness bands, it has become easy and common to measure your heart rate. There are however fundamental differences in sensor types. Some sensors capture the electrical signal from your heart while others use light to analyse the blood flowing through your vessels. If you're interested in measuring heart rate, it's good to understand these differences.
This month our Babboe Big cargo bike arrived, in boxes. The engineer in me thought it was a good idea to assemble the bike by hand. This way I would know exactly about all its parts and fittings, handy knowledge for maintenance. Read along for my experience and some practical tips.
This week I took my bike for a long distance (211KM) ride around the Dutch Markermeer, solo! Unlike participating in an organised event with service, support and company along the way, going solo requires a different preparation, mindset and planning. Read along for some practical tips for long distance cycling.
This month I have intensified my training to become fit for this year's Fietselfstedentocht, a 235KM bicycle ride through Friesland. Over the years I have tested different kinds of bike computer setups: from dedicated (and expensive) Garmin Edge bike computers to no data at all. Eventually I came up with a flexible setup to gather advanced ride data using my smartphone, let me explain how this works.
A year ago I tried to create the ultimate commuter bike, a modified Sensa Cintura with the Gates CDN/CDX carbon belt drive. I received lots of messages from cyclists and commuters from all over the world. From the Swiss alps, France, Italy, Germany, United States and even "down under", Australia! You all wanted to know: how does the upgraded bike hold up?
Over the past few months I have been testing different bags and cases to fit everything I need to run my business. As I commute by bike, the bag needs to be waterproof. The problem with waterproof gear is that it is usually very bulky. I need my gear to be both portable and representative, a challenge worth a blog post!
This month Apple launched a new Apple Watch series and released an update to watchOS. The focus of the smartwatch is more and more gearing towards health and fitness. This made me curious, how well does Apple Watch work for different activities?
There is beauty in raw, unfinished material that is often hidden with superfluous layers of paint. I like things to be true to the nature of the material. My bike was painted black - not bad - but I wondered what it really looked like from a material point of view.
A good customer of mine was once a physiotherapist, he told me about people asking him to "feel their muscles" to tell them how they where doing. "Crazy!" he told me: "I can never feel better than the people themselves, if they only would listen to their body". This caused me to question the health and fitness sensors I use.
This winter I use a Sensa Cintura bike with a Gates Carbon belt drive as my daily commuter. It's a bike designed to be nice to ride thanks to its sporty lightweight frame. It's also meant to be low on maintenance thanks to the belt drive and Nexus Afline 8 integrated gear hub. After 1800KM in just eight weeks, it was time for some upgrades.
For a few years now, I commute to work using a bicycle. I have lost more than 15KG since I stopped using my scooter. This week I tested a VanMoof Electrified S, an electric bike with an industrial, minimal design. Is it any good? How does it compare to a normal bike? Will an electric bike make you lazy? Read along to find out!
Most wearables (smartwatches, fitness trackers, etc.) use very basic sensors to capture heart rate. Their signal is binary: just counting beats. Biostrap is different, instead of just checking pulses, it captures a high-fidelity PPG waveform. These waveforms are the same kind that doctors use, making me wonder what I could learn from them!
This month I cycled the Fietselfstedentocht, a 235KM tour through Friesland. This tour brings you through various Frisian cities throughout one of the most Northern provinces of the Netherlands. The tour was first organised in 1912 and has grown to become legendary due to its history, challenge and popularity; well worthy of a blog post!
This month I received an invitation to join Mercedes at the Zolder circuit in Belgium to drive in "the beast". The Mercedes-AMG GT R, a furious green coloured performance car that gets its nickname from the Nürburgring where it was developed. It was an incredible experience, well worth a blog post!
One year ago I started recording all my bike rides, including commutes, short grocery trips and long Gran Fondos. I equipped my bicycles with Garmin Edge computers that recorded location (GPS), speed, cadence and my heart rate. I covered more than 7683 kilometers during 320 hours of riding. It's time to review all the data and share some photos I took along the ride!
Almost a year ago I bought an old steel racing bike from 1978. I wanted to figure out if using a bike to commute worked for me. It did! I used it to ride more than 1000KM before I decided to get a modern road bike. Now, almost a year later, I decided to put the powers of the internet into good use: to bring the bike back to its retro glory!
