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 kept growing after the pandemic: according to the Health & Fitness Association, global memberships rose 6% in 2024 and revenue grew 8%. In HFA's latest published benchmark (April 7, 2025, covering 2024), U.S. gym membership was also up 20% vs 2019, confirming post-pandemic expansion into early 2026. (Global 2025) (U.S. 2019-2024)

The bottleneck most coaches face is operational:

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.

That does not stop coaches from taking more clients. It changes the quality they can sustain.

That is how the industry quietly drifts into generic programming: same structure, same progression, same template for people with very different goals and constraints.

Personalization should not be a luxury for elite athletes. It should be the baseline for anyone paying for a personalized service.

The conversation that triggered everything

Kaizer did not start as a theory. It started as a real conversation.

In late 2024, during a chat with his personal trainer, Agustín Anfosso (Kaizer's CEO) heard something obvious and frustrating: scaling high-quality coaching felt almost impossible. The coach was turning down clients to avoid lowering quality.

From the client side, Agustín had the same friction: spreadsheet-based plans were hard to follow on mobile, hard to track, and hard to understand week over week.

A messy start

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

We were building something that did not really exist in practice: software that helps coaches scale personalization without turning coaching into admin work. No clear map, constant improvisation, real-time learning.

Our first prototype was basic: AI that delivered plans in spreadsheets. That made one structural issue obvious: much of the market still runs on formats that are hard to follow and even harder to adjust week to week without confusion.

When it clicked

The breakthrough came when we realized something simple but powerful:

With text inputs, we could generate hyper-personalized routines that reflected real client constraints and updated week over week based on performance, goals, preferences, experience level, injuries, and limitations.

That is when we understood the core: this was not about AI-generated content. It was about turning real-world constraints into correct programming, fast.

The team

To build Kaizer the right way, Agustín partnered with:

• Pedro Guarga (Co-Founder & Head of AI & Data) — Master's in Artificial Intelligence and experience at OpenAI, leading a critical layer of the product.
• Octavio Serpe (Co-Founder & CTO) — engineer trained at one of LATAM's top universities and former Senior Engineer at Mercado Libre.

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."

The first clients

We did not grow through ads or big partnerships in the beginning.

We grew through direct conversations, one by one.

Our first client was Turco Fitness Coach, one of the most recognized coaches in Argentina, known for training international 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.

If you want to train with him, you can message him directly here.

The mistake we made early on

One of our early assumptions was that adoption would be immediate.

They didn't.

People are skeptical of new tools, even when the upside is obvious. The pattern repeats in every tech cycle: unfamiliar feels risky until it becomes normal.

We learned a core rule: building trust matters as much as building product.

Where Kaizer is today

Today, Kaizer is used by 150+ personal trainers, supporting 3,500+ clients with truly personalized training and stronger service at scale.

Our goal isn't to replace coaches.

It's to give them leverage: less time on repetitive planning, more time on coaching, accountability, and client outcomes.