Kaizer Started With a Sunday Problem

Most great coaches don't lose clients because they don't care.

They lose them because scaling care is brutally hard.

The fitness industry has grown massively post-pandemic, but one thing hasn't kept up at the same pace: the quality and personalization of what end users receive. Not due to a lack of professionalism (if anything, most coaches work incredibly hard) but because the industry still lacks the right tools to scale a truly personalized service without burning out.

Here's the constraint almost every coach eventually hits:

A coach who creates personalized routines, tracks performance, and updates training week after week spends around 30 minutes per client per week just on programming adjustments. With 10 clients, that's roughly 5 hours. With 50, that becomes 25 hours every week spent doing only one thing: updating routines, often on Sunday afternoons, once everyone has trained and the coach finally has enough data to plan what's next.

This doesn't stop coaches from taking on more clients. It just changes the service.

And that's how the industry quietly drifts toward generic programming—same structure, same progression, same "template," for people with completely different bodies, goals, preferences, schedules, and limitations.

It's like giving an entire soccer team the exact same gym routine. In a real performance setting, that makes no sense: a goalkeeper benefits from training that improves lateral power, reaction time, and joint resilience, while a striker needs more emphasis on speed, explosiveness, and shot power. Same sport, different position, different needs. The same logic applies across all sports, and honestly, across all humans. Personalization shouldn't be a luxury reserved for professionals. It should be the baseline for anyone paying for a "personalized" service. Because when people don't feel the plan fits them, results slow. Then they quit. Sometimes they quit the coach. Sometimes they quit training altogether.

The conversation that triggered everything

Kaizer didn't start as a theoretical idea. It started with a real conversation.

In late 2024, during a chat with his personal trainer, Agustín Anfosso (Kaizer's CEO) heard something that was both obvious and frustrating: scaling high-quality, personalized coaching felt close to impossible. In this case, the coach wanted to maintain quality, so he was turning down new clients simply because he didn't have time to program properly for more people.

Agustín went searching for a tool that could solve that problem for his coach, but he couldn't find one.

A messy start

Kaizer officially started in January 2025, and the first week was extremely hard.

We were trying to build something that, in practice, didn't really exist yet: software that helps coaches scale personalization without turning coaching into admin work. We were improvising constantly, with no clear map, and learning in real time what the product needed to be.

Our first prototype was rough. It was an AI that delivered routines in spreadsheets, which sounds normal until you realize how much of the coaching experience still works like that. In our conversations across Latin America, spreadsheets are still the default delivery format for a huge portion of personal trainers, and that makes the end-user experience unnecessarily painful: hard to follow, hard to stay consistent, and almost impossible to adapt week-to-week without chaos.

The magic!

The breakthrough came when we realized something simple but powerful:

With just text inputs, we could generate a hyper-personalized routine that genuinely reflected the client's reality and updates week over week based on performance: goals, preferences, experience level, injuries, limitations, and still followed the core patterns that evidence-based training requires.

That's when it clicked: this wasn't about "AI content." It was AI that translates real-world constraints into correct programming, fast.

The perfect team

To build Kaizer the right way, Agustín partnered with:

• Pedro Guarga (Co-Founder & Head of AI & Data) — with a Master's in Artificial Intelligence and experience working for OpenAI and other top AI companies, making him the right person to lead what is a fundamental part of Kaizer.
• Octavio Serpe (Co-Founder & CTO) — an engineer trained at one of the top universities in LATAM, and former Mercado Libre Senior Engineer (a company known for an extremely demanding hiring bar and engineering culture).

From day one, the focus was clear: speed for coaches without compromising quality.

The first proof it worked

The same coach who sparked the original conversation used Kaizer and scaled from 10 clients to 50 clients in one month, without losing quality.

That's the kind of result that changes how you see the problem. Because the constraint was never "lack of demand." It was "lack of time."

Our first clients came from cold DMs

We didn't grow through ads or big partnerships at the start.

We grew through cold DMs.

Our first client was Turco Fitness Coach, one of the most recognized fitness coaches in Argentina, who has trained internationally known artists like Rusherking, Khea, and Lit Killah, among others. Today, he manages 100+ clients using Kaizer in his day-to-day, scaling without turning his service into generic templates.

The mistake we made early on

One of our biggest early assumptions was thinking that everyone would instantly love this technology.

They didn't.

People are skeptical of new tools, even when the benefits are obvious. It's not that different from how earlier generations doubted computers or mobile phones (we all heard the myths from parents and grandparents). The pattern repeats: unfamiliar tech feels risky until it becomes normal.

So we learned something important: building trust matters as much as building product.

Where Kaizer is today

Today, Kaizer is used by 50+ personal trainers, supporting 1,500+ clients with truly personalized training and a better service at scale.

Our goal isn't to replace coaches.

It's to give them leverage, so they can spend less time doing repetitive planning, and more time doing what actually moves the needle: coaching, accountability, and client success.