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My name is Feike Dirks from the Netherlands. In 2018 I was diagnosed with McArdle’s at age 60, and that is late. First, I will try to give you an idea of the kind of life-changing event a late diagnosis is. Then I will write about my experience at the McArdle Walking Course in 2019.


Feike Dirks




McArdle’s (GSD5)


Age 60


Age 63




Not all 600 muscle diseases are progressive or fatal. McArdle’s disease is not, even if you suffer from it daily. But if you handle it wrong, it can turn into a kind of wrecker. You could say that McArdle’s is ‘conditional progressive’: it creates conditions that cause progressive muscle weakness if you don’t handle them well. You can’t start too early to learn to handle them well. I hope my story will underline this.

A very late diagnosis

I have had problems with exercise and activity all my life. I still can vividly remember several episodes at primary school and high school where McArdle’s got me into some sort of trouble. Like so many other McArdlers I developed an extensive personal trick book to avoid getting into trouble: leaving early for school and leaving late from school to avoid having to cycle or walk with others, things like that. This continued in university and in my working life as a teacher in high school. The problems persisted. I visited doctors regularly, had my heart checked a couple of times but nothing came up.

The medical advice always was: “Eat less, exercise more” and “It’s in your head”. So, I became a member of a gym, learned the ways of the treadmill and the weight-lifting torture machines. One time I got home from the gym and said to my wife “That back exercise machine doesn’t feel good”. But it was part of the recommended personal training program, so I endured. I made near to no progress in a year of regular gym sessions. The gym people rigged the electronic fitness test to make me feel better about myself, but if you notice a plot like that, it doesn´t work. I even at one point had my head examined, so to speak. That didn’t help either.

When I turned 50 things started to worsen

I got into more and more trouble getting around in the school building, using the stairs, walking around in the classroom, lifting books and laptops, writing on the blackboard, and standing up straight. After school hours I sometimes needed up to 30 minutes to work up the courage to walk back to my car. In 2017 my wife and I stopped accepting the standard advice from the doctors and pressed for better answers. A string of investigations followed that all turned out to be a wild goose chase.

A neurologist, who himself could not find much wrong with me apart from a persistently high level of CK, referred me to a university medical center that specialized in muscular diseases (Radboud UMC, Nijmegen). My wife and I were convinced this again would turn out to be a wild goose, but that was not the case:  it became the turning point! Already in the first visit the doctors in Nijmegen were sure it really had to be a muscular disease and they were going to find out which one. They gave me a shortlist with the advice not to Google this list. Our initial reaction was one of big relief. Of course, the Googling (which I did anyway) added a layer of seriousness to the relief, but the feeling didn’t disappear.

A puzzle solved

A few months later it became clear that it was McArdle’s through a not so nice biopsy and physically much less invasive DNA research. A scan made clear that there was muscle damage in several parts of my body, and some of that damage was irreversible.

The impact of such a a diagnosis is immense! It makes you re-interpret big parts of your life from the new perspective.  It really is a puzzle solved!

A rehabilitation program followed. The main goal was “re-inventing your life”. It involved learning to recognize my limits and managing my kind of disability. (NB: this will differ greatly from one McArdler to another!)  The most drastic change was the end of work. In this ‘re invention’ program the walking course of IamGSD played a big part, in more than one way...

Scroll though my photos. Click to enlarge.

The 2019 Walking Course

How do you get rid of all kinds of bad habits or expectations and develop good new ones? Medical professionals and fellow sufferers can help you with this. Because it is such a rare disease, you soon look across the border in the search for that kind of help. IamGSD was quickly found.

One of the activities of IamGSD is the McArdle walking course, documented on In 2019, a year after my diagnosis, I participated in this course. It was held in beautiful Pembrokeshire in South Wales, close to the coast. Thirteen fellow McArdlites participated in the course, most from Scotland, Wales and England, but also from the Netherlands (yours truly), Germany, Australia and the United States. The lead was in the hands of Andrew Wakelin.

The course mainly consists of a daily walk of between 8 and 15 kilometers. During the walk there are instruction moments about the best way to approach such a walk from a McArdle perspective. Several exit points in the walk are intended for those who don’t feel up to finishing the walk. The pace during the walk is McArdle-friendly, and there is certainly no question of a marching pace. Attention is paid to technique, for example the use of walking sticks to distribute the scarce muscle power between arms and legs. Also, the managing of slopes and descents is discussed (zig-zag techniques) and the application of all kinds of typical McArdle mantras (memory aids). One of those mantras is: thirty-for-eighty: If your muscles are out of energy (a McArdle characteristic) you need to rest for at least 30 seconds to get 80% of the immediate energy back in your legs. Then you can continue for a while. On a steep slope or a long stretch such a mantra regularly buzzes through the group. One of the course rules is that if someone needs 30 seconds of rest the whole group will stop and “not talk about it”. Every McArdler knows what it is like to feel guilty when you stop the group you walk with (e.g., family, friends, work colleagues) because you can't go on.

A lot of attention is paid to using “second-wind”. That is the situation in which fat burning takes over the energy supply from carbohydrate burning (you simply cannot hardly have with McArdle). That way you learn that sometimes you can handle more than you thought beforehand.

Respecting your limits

Still, during a few walks I had to opt out halfway. That's not a fun experience (“I can’t even keep up with my fellow McArdlites”), but a useful one! That way you learn to better respect your own limits. Those limits differ from person to person in people with McArdle’s, due to things like age, other medical issues, and the time of your life that you were diagnosed.

In the evening sometimes there is a chat from an expert. And there is plenty of time for mutual exchange of experiences and normal conviviality among McArdlites. This part was of great value to me because you don't talk to a fellow McArdler that often. There was a lot of recognition, in big things (life choices) but also in small things ("Who can climb a rope?" Wide grins: "Nobody!"). Experiences with all kinds of diets, doctors, therapists, or social services were exchanged and there was always something of interest to think about. But you also see the differences, for example due to additional illnesses that someone has or due to a different organization of care in a country.

You won’t forget a week like this

Especially the recognition in fellow McArdlites is something from which you can derive permanent support. One moment will always stay with me: after a trip to an island off the coast, our boat came back to the coast during low tide and landed on the beach because the tide was out and the harbour empty. So, our group had to walk about 150 metres through the loose sand to street level. You can’t do that all at once with McArdle. So, our entire group walked about 25 metres, stood still chatting (“30 for 80”) and after half a minute walked on again. That repeated itself several times. It must have been a strange sight to the other people on the beach. But we didn't care, we got there our own way!

And now, is re-inventing complete?

The bulk of my walking and stability problems have not gone away. But now I know better what their cause is and how I can prevent worsening of the problems. It is therefore easier to live with. My wife and I have a couple of (voluntary) exercise sessions each week. Twice a week we make a bike tour of 15 – 25km. The e-bike is ideal because you regulate the support the ebike-motor gives you: the first minutes you let him work harder than later in the ride. We only skip these rides when there is dangerous weather (icy road, thunderstorm). Whenever I must do some shopping in town, I use the ebike (and not the car).

I have a one-hour physiotherapy session every week where special attention is paid to stability in walking, sitting down/standing up, and stair-climbing. These therapy sessions always start with an ebike ride (to the physiotherapy clinic), a treadmill walk, and a hand-cycle session to get as much of me as possible into “second-wind”.

I try to maintain a good balance between activities at home (reading, making music) and activities outside home (again making music, visiting people or places). This overall process of re-inventing my life is ongoing. The recent pandemic proved that once more.


I am convinced that if people know they have McArdle’s earlier in life they can make reasonable and good adjustments in the way they approach activity, exercise, work, and life itself so they can prevent bigger muscle problems. IamGSD has a campaign objective to see the reduction of the average age of diagnosis to below 10 years of age.

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