A Simple, AI-Powered Approach to Building a Personalised Fitness App

Over the last few months, I’ve been deep in my own personal health reset, understanding what strength, mobility, and recovery look like for women.

Somewhere in the middle of creating exercise libraries, weekly schedules, and “long sitting recovery” routines, a thought appeared:

Why not turn this into a simple fitness app for myself and my family?

And thanks to Lovable, the AI-powered web app builder that idea turned into an actual working prototype faster than I expected. What used to require a development team can now be built through a single structured prompt and vibe coding.

Vibe coding is a modern software development approach that uses AI (like large language models) to generate code from simple, natural language instructions.

Using AI to Build the App

Lovable makes it possible to create full-stack apps with one prompt. I used the exact specification the platform generated for me, and it produced:

• Authentication

• A database

• A full UI

• A stretch timer

• An exercise library

• AI-generated images

• And even analytics dashboards

...in minutes.

Seed Exercises

I used the full set of exercises I’ve been compiling from multiple articles online, from Deadbugs and Pallof Presses to Glute Bridges, Cat–Cow, Standing Arm Pulses, and more. Lovable automatically built them into a real database.

What I Learned About Building Apps With AI

Working with Lovable made me realise:

1. AI accelerates what you already know.

The more clarity you have, the better the app becomes. The prompt wasn’t “make me a fitness thing. ”It was:

• Here are my tables

• Here are 18 exercises

• Here are two plans

• Here is the stretch sequence

• These are the pages

• These are the UI expectations

• Here are the security constraints

AI shines when you bring context and structure.

2. Custom apps are becoming deeply personal.

This is a fitness app built specifically for:

• My stage of life

• Our actual routines

• Our biomechanics

• Our time zone

3. The barrier to entry for app creation is disappearing.

With a thoughtful prompt, you can build:

• A fitness app

• A journaling app

• A creativity app

• A mentoring app

• A habit app

…without touching a line of code. While Vibe Coding is not yet ideal for all apps - it is ideal for a customised simple app like this one.

Creativity + Clarity + AI = New capability.

Where This Goes Next

I’m planning to add:

• Video clips of correct form

• A “recommended weekly plan generator”

• A guided warm-up and cool-down

And, perhaps in the future, an AI Coach layer that gives personalised suggestions based on progress.

Final Reflection

This project was a wonderful example of how AI can help us build the tools we need customised for what we need. As someone who believes in the democratisation of AI, this felt like a natural next step.

I now have a fitness app shaped around exactly what matters to me, balanced strength, mobility, and longevity. If you are curious about building your own wellness, creativity, or productivity tool, the barrier has never been lower. All you need is an idea, a clear prompt, and the willingness to experiment.

Here is the complete guide and prompt for the Exercise App if you would like to build your own:

Prompt for Lovable Exercise App.pdf

Download PDF • 239KB