I Fired My Coach. Hired an AI. (The 42km Experiment)

80% of professional parents who try to run a marathon break down or quit before the starting line.

It's not because they lack discipline. It's because they're using a static plan for a dynamic life.

I'm 40+, with 19 marathons behind me and a Tech Lead job. And I'm going to tell you an uncomfortable truth: Paying a "human" coach to send you a static PDF over WhatsApp is throwing money away.

Don't get me wrong — there are great coaches out there. But they're expensive and most don't specialize in profiles like ours (parents with an exploding schedule).

Most treat you like an elite athlete with free time, or send you the same generic plan they send everyone ("Average").

For my last two marathons, and especially for Buenos Aires this year, I did something many considered crazy: I fired the humans and put my preparation in the hands of Artificial Intelligence.

The result?

• Crossed the finish line in 3h:14m (my second-best time ever, right on the edge of qualifying for Boston).
• Didn't get divorced.
• Didn't get fired.
• Arrived in one piece.

The Hell of the Rigid Plan

A few months ago I was in "amateur runner hell." I had a plan stuck to the fridge that said: "Tuesday: 12km with Fartlek."

But my real Tuesday was:

1. Max sick → took him to the doctor.
2. Emergency production meeting.
3. Mía refused to sleep until 11pm.

I looked at the plan on the fridge. The plan looked at me. I felt that toxic guilt of someone who "doesn't follow through." I went running anyway, slept 5 hours, and the next day I was a zombie in the standup.

That's when I said: "Enough."

It can't be that at work I use Agile methodologies that adapt to change, but for my health I use a "Waterfall" paper system that ignores my reality.

I decided to hack the system.

Rigidity Is Fragility

They sold us the lie that discipline means "doing what the paper says no matter what." And don't you dare question it.

That's mathematically impossible if you're a parent with responsibilities.

Life's entropy always beats your spreadsheet.

The truth nobody tells you: Rigidity isn't strength.

Rigidity is fragility. If your plan breaks because you had an extra meeting, your plan is garbage.

Average forces reality to fit the plan (and breaks down).

Above Average creates a Dynamic System that adapts to reality in real time.

You don't need more willpower. You need more adaptability.

Adaptive Training Protocol with AI

Here's how I built my own system. It's not magic. It's data engineering applied to the body. I used Gemini (you can use Claude or ChatGPT) and created a specific "Gem" with these 3 steps:

1. Context Ingestion (The Master Prompt): Don't ask "give me a marathon plan." That's amateur. You need to give it your hard constraints. My initial prompt included:

"I'm X years old. I weigh X kg. My VO2 Max is X. I can train 4 days, not 6. My heavy work days are Thursdays. My best recent half marathon time was X. Goal: Buenos Aires Marathon in 16 weeks."

That's the simple version — the more detailed you make it, the better. Take that output to an Excel or Notion. That's your map, but the map isn't the territory.

2. The Daily Feedback Loop: Every morning, I feed the AI my recovery metrics (HRV and Sleep from Garmin) and my schedule.

Prompt: "I slept badly today (Score 40) and have 3 hours of back-to-back meetings. Adjust today's training so I don't burn out."

3. The Live Recalculation ("Recalculating..."): If I couldn't train on Tuesday, the AI doesn't make me feel guilty. It recalculates the weekly volume and redistributes it.

The secret: I manage 3 horizons (Optimistic, Realistic, Pessimistic). If the week gets complicated, the AI switches to the "Pessimistic" plan to save minimum volume without breaking me. The important thing is to arrive at the start line and complete the marathon in the worst case.

Result: Zero Burnout

I ran the 42km of Buenos Aires achieving my best time in 10 years. But the real number isn't on the clock.

The real number is: ZERO BURNOUT.

• I always maintained my energy to play with Max and Mía.
• I didn't drop my performance on work and personal projects.
• My injuries stayed controlled because AI stopped me when I (out of ego) wanted to accelerate.

Cost: $20 USD subscription. Gain: Peace of mind and health.

The free versions of any AI will never give you the "care" that a paid one does.

The cost of 4 coffees per month on something that can literally change your life in many ways and make you Above Average — it's worth it.

Maybe all this works for me because I'm a "Lone Wolf." My schedule doesn't allow for going to the trendy Running Club to socialize. I need pure efficiency.

Your Turn

Coaches aren't going to disappear. If you need someone to yell "come on!" and send you motivational stickers over WhatsApp, pay for one.

But if you know what you're doing (gym, running, triathlon) and want to optimize your life, delegate planning to AI.

Your task for today: Take your current plan and feed it to AI with this prompt:

"Act as my high-performance coach. I'm 40+, have kids and little time. Optimize this plan to be sustainable, not ideal. Prioritize longevity over maximum performance."

Stop training for the ideal scenario that never happens.

Train for the life you have — and be Above Average.

See you on the road.

Pablo Marichal Above Average