How to do a SkiErg marathon entirely the wrong way (but still finish)


How to eat the wrong way, rest the wrong way (i.e. not), half-ass all relevant parts of preparation for a marathon and still finish with an okay time.


Chris von Csefalvay


13 October 2023

Yesterday, I completed a marathon on the SkiErg, with a pretty respectable time (see results here). I know I can do better, and I know I will do better. On the other hand, this was a marathon where I pretty much did everything wrong. And that was sort of an instructive experience in its own right.

The title is somewhat misleading. Not much went wrong – the marathon itself was smooth sailing. At a 2:34.6 pace (min/500m), it was one of my better very long distance pieces – my ranked half-marathon pace at the time was 2:30.7, and that was a very intentional, very prepared piece. There were also really no unexpected surprises in the process. On the other hand, I built up to this marathon the in worst way possible.

What worked for me

It’s probably important to be realistic ahead of all: I did go into this madness with some assets.

  • For one, I’m a multiple world record holder in my adaptive class. I know a thing or three about the SkiErg, and as a former rower, I’ve got every rower’s love-hate relationship with the erg.
  • I’m a former multisport athlete, and I’ve been doing a lot of long distance pieces. I know how to cope with the boredom. Most people who go into a marathon have done a half, and maybe a 30k piece. I’ve done several split marathons in the past few weeks, as well as several 30k pieces.
  • I’m probably in a pretty good state of overall fitness. I have enough of a gym habit to qualify as not exactly a couch potato. There’s a lot you can get away with if you have a decent \(VO_{2_{max}}\), and even though I’m in a wheelchair, I do enough activity to stay in good enough cardiovascular fitness.
  • I have an incredible boredom tolerance. Marathons are primarily psychological: we’re just not used to doing the same one thing, without interruption, for 3-5 hours anymore.
  • I guess insofar as there’s such a thing as a genetic predisposition to be good at long distance physical activity, I’ve got the right genes. My dad is a multi-marathon athlete, so I likely have the right physiology.
Figure 1: Stroke level data for the SkiErg marathon.
Source: skierg-marathon.ipynb

How not to do a marathon

There are generally three commonly accepted things to do for a good long distance piece:

  • get some rest,
  • carb load, and
  • if you’re not doing an organised race, have someone check in on you and help with things like hydration.

I’ve done exactly zero of these things. For starters, I did my marathon in the middle of 75 Hard, which in retrospect was not the best of ideas, as it meant that (1) I wouldn’t be able to take days off to rest, and (2) I wouldn’t be able to carb load as that would be outside my diet. I’ve also decided to do all this while my better half was away visiting family, so I was pretty much on my own.

At 2am.

Figure 2: Stroke level data of stroke length (metres) versus stroke duration (seconds).
Source: skierg-marathon.ipynb

Yes, that’s not a joke – I decided to do my marathon at a time when the world is falling apart at the seams, and so the only time I could find during which I could hope not to be interrupted with the latest crisis was late at night. So I woke up at 0130 hours, much to my dog’s chagrin, and headed down to my apartment building’s gym to torture myself for a few hours before the sun came up. Fortunately, the world decided to behave for those three and a half hours.

I tried to counteract this to some extent by doing something I generally dislike: carbohydrate gels. A long, long time ago, in a galaxy far away, I ran the Watford half-marathon when I was still into actually running (by far the only reason I remember where that half-marathon was is because it was so miserable). It was a bitter cold day, and it actually started snowing in the middle of the damn thing. To keep myself mostly sane and nourished, I took some of these 100kcal sachets of carbohydrate gel. What I didn’t know, of course, was that that stuff would glue your mouth together unless you consumed enough water… which I didn’t. Bad idea. On the other hand, I am now older, wiser and able to afford much better and less sticky-tastic carbohydrate gels, so I thought I was going to have some. I didn’t feel much of an effect one way or the other. At one 100kcal sachet for every hour, I paced it a little slower than is commonly recommended (one sachet per every 45 minutes seems to be the consensus recommendation), but really didn’t feel much of an effect either way. In retrospect, I probably wouldn’t bother doing it again.

As for rest, the best I could do is not do a long distance piece the day before the marathon. Indeed, I only did a relaxing 2k that day, which is about a fifth of my average daily SkiErg distance. Nevertheless, I think it was quite clear that with my ultra-low-carb diet, no carb loading and at best minimal replenishment (my average burn rate was around 5-600kcal/hr, and I took in 100kcal via the carbohydrate gels, so pretty much a drop in the ocean), I was running on fumes for most of it.

Incidentally, my marathon time is also the SIT2 world record for my age group.


My key takeaway from this experience was that we all should do a marathon under suboptimal conditions. Yes, doing a long distance piece at Bataan death march levels of calorie deficit is probably not super healthy, but you learn some interesting things about your body in the process. For starters, I think it was an interesting illustration of the fact that one’s overall level of fitness – especially \(VO_{2_{max}}\) – matters a lot more than game day conditions. You can get away with a lot if you’re fit enough, up to and including running the show in quite sub-optimal circumstances.


BibTeX citation:
  author = {Chris von Csefalvay},
  title = {How to Do a {SkiErg} Marathon Entirely the Wrong Way (but
    Still Finish)},
  date = {2023-10-13},
  url = {},
  doi = {10.59350/68s7b-8c778},
  langid = {en-GB}
For attribution, please cite this work as:
Chris von Csefalvay. 2023. “How to Do a SkiErg Marathon Entirely the Wrong Way (but Still Finish).”