Three weeks ago, I signed up for a marathon. The race takes place on the 21st of September. In total, this leaves me with 20 weeks of preparation.

I now completed the first 3 weeks.

Here is what I've done so far and what I've learned.

To set myself up for a good preparation, I watched a few videos about long-distance running and training principles one should implement.

Basics of long-distance running

• Training for a marathon, you want to increase your endurance base.
• To train your endurance base, you want to train easy most of the training sessions.
• As a rule of thumb, 80% of your training should be spent in zone 2. The other 20% should be spent doing speed training.
• Zone 2 training evolves around a training effort that leaves you with the capacity to hold a conversation during running. But you would rather not hold that conversation due to the effort (opposed to training in zone 1).

• To help your tendons, ligaments, joints, and muscles adapt to longer distances, you should increase your weekly running volume gradually and steadily.

I just downloaded a 20-week beginner marathon training plan that I want to stick too during my preparation.

Week 1

I started easy. One 6 km run on Thursday and another 9.2 km run on Sunday.

Total: 15.2 km

The first 'run' really got me frustrated. I tried really hard to run in zone 2, which for me is allegedly ranged from a hearth rate of 138 to 155 bpm. Although running real slow and even walking in between, I did not manage to get my hearth rate below 160 during my first run.

The second run started just the same. Then I told myself, “Ok. Fuck it. I just run at whatever heart rate and get into a flow.” This way I managed to keep a steady pace during the second half of the run and to get my hearth rate in zone 2 (below 155 bpm).

Although I ran slower than I've ever run before, this felt like a major accomplishment after failing to stay in that effort zone real bad during the first run.

Week 2

In week two, I completed five runs in total:

• Monday: 8 km
• Wednesday: 6 km
• Thursday: 6.2 km at marathon pace (zone 3)
• Friday: 7.9 km
• Sunday: 11 km

Total: 39.1 km

Week two was the best week I had so far.

I consistently managed to run in zone 2, and I got faster running in that zone from run to run. My running became a lot smoother and (at least felt) more efficient. However, till the end of the week, my legs got really fatigued. A more than 50% increase in running distance per week might be too big. However, I just decided to follow my plan (which is a beginner marathon plan, after all).

Week 3

This week, I completed 4 out of the 5 planned runs:

• Tuesday: 9.5 km
• Wednesday: 6.2 km
• Thursday: 6 km at marathon pace — skipped
• Friday: 7.7 km
• Sunday: 11 km

Total: 34.4 km

The fatigue really started to hit this week. My legs were still wrecked from Sunday’s long run, and the soreness carried over into the first half of the week. I ended up skipping the Thursday run at marathon pace—my legs just weren’t having it.

Toward the end of week two, I began to notice the early signs of shin splints, and this was the first week when recovery clearly became a priority in my training. If I want to make it through 20 weeks of training, I should avoid burning out in week three.

In total, I’ve logged roughly 89 km so far. My estimated VO2 max (a common measurement of aerobic fitness) was estimated to be at 48 at the beginning of my preparation and rose to 49 by the second week. Not sure how accurate that is yet, but we'll keep an eye on that.

One thing’s clear: I’m learning a lot—especially during the long runs. Those are where I get the most insight into my running form. I’ve noticed something off with my left leg. By the end of week two, it started feeling strange during runs. I think I’ve found the issue: I tend to roll over the outside of my left foot too much. I'm still experimenting with slight changes in foot placement and stride to see what helps.

The next few weeks will show whether I can maintain the planned volume without overdoing it.