What an 11-Hour Ironman Taught Me About Seven Months of Focused Work

In 2016, I signed up for the full Ironman Maastricht: 3.8 kilometres of swimming, 180 kilometres on the bike and a marathon.

I had not built my identity around triathlon. I was young, relatively fit and thought I could probably finish if I worked at it properly for seven months.

Armand van der Smissen, the 11-time Dutch national champion who trained our Tilburg University triathlon team, thought the attempt was absolutely mental. Maybe even stupid.

He had the experience to see every way it could go wrong. I had enough inexperience to believe it might go right.

The plan was not heroic

I trained. Then I trained again the next day. I learned to swim more efficiently, accumulated hours on the bike and made running familiar enough that it no longer felt like an emergency.

I used two quarter-distance triathlons and one half-distance race as practice. Each one made the unknown smaller. Equipment choices became less dramatic. Transitions became a routine. I learned what food my body tolerated and what pace felt sustainable after several hours.

I never ran farther than 21 kilometres in training.

That detail sounds reckless when isolated. It is not advice. Endurance preparation is personal, and poor training decisions can cause real harm. What mattered in my case was the larger body of consistent work, the cycling volume, the supervised training environment and the restraint to treat race day as an exercise in pacing rather than ego.

The finish was built on ordinary days

The finish line photograph suggests one extraordinary day. The actual achievement was created on hundreds of ordinary ones.

No single training session transformed me. A few focused hours repeated across seven months changed what my body, mind and identity considered normal.

This is the part people underestimate in business too. They compare today’s ability with the final standard and conclude the distance is impossible. They rarely picture the capable person or company that seven months of deliberate repetitions could produce.

Practice events turned fear into information

The shorter triathlons mattered because imagination is a poor risk model. Before the first race, everything feels uncertain at once. After it, uncertainty becomes a list.

The wetsuit rubs here. The bike nutrition needs changing. The first kilometre of the run feels terrible and then settles. The transition bag needs a different order.

In business, a small launch, paid pilot, customer interview or public draft plays the same role. It converts vague anxiety into observable improvements.

I accidentally changed how people saw me

The strangest return appeared after the race.

For roughly two years, people across my first, second and even third-degree network treated me as if I possessed unusual grit. Many had not seen the training. They saw a recognisable, difficult result and updated their belief about what I might be capable of elsewhere.

Perhaps they were a little right. Finishing did require stubbornness. But the mythology was larger than the daily reality. I had not discovered a secret reserve unavailable to normal people. I had decided, organised the work and continued long enough for the result to become possible.

Achievement creates transferable proof

A difficult visible result communicates beyond its original category. An endurance race can signal discipline. A published body of useful writing can signal judgment. A customer case can signal that a method works under pressure.

That signal should not be confused with universal competence. Finishing an Ironman did not make me automatically good at strategy. But it gave people a reason to believe I could commit to a long, uncomfortable process.

The best personal proof is specific enough to be credible and modest enough not to become theatre.

What I would tell the younger founder

1. Choose a finish line that changes your behaviour now.
2. Find people who understand the risk better than you do.
3. Use smaller real tests, not only private preparation.
4. Make the daily work small enough to repeat.
5. Let the result become proof, but do not let it become your whole identity.

Seven months is short enough to imagine and long enough to become meaningfully different.

You may not need superhuman grit. You may need a clear decision, a few honest hours today and the willingness to do it again tomorrow.