How to Build an AI Fitness Video Analysis App in Lovable in 30 minutes

👉 Watch the live build here: YouTube demo

Ever thought: “I work out at home, but how do I know if my form is right without hiring a trainer?”

That’s a real struggle for home fitness fans. You want guidance, but you don’t have a coach standing next to you.

Good news: with today’s no-code tools, you can actually build your own AI-powered fitness coach — one that checks your posture, evaluates your plank form, and gives structured feedback automatically. No coding, no hassle — and yes, it can be done in under an hour.

What We’re Building

An AI fitness app that works like a personal coach. To keep it simple, we’ll start with plank form analysis — because planks are one of the most common, effective, and tricky exercises people do at home.

Why plank?

• It looks simple, but small mistakes (like sagging hips, raised shoulders, or uneven weight distribution) can reduce effectiveness and even cause strain.

• It’s a perfect MVP case: clear posture checkpoints, short video inputs, and high value for users who want feedback they can actually apply.

Here’s what the app does in this first version:

• Upload a plank video (just a few seconds is enough).

• Automatically analyze posture across the core, arms, hips, and shoulders.

• Get structured feedback: an overall score, a body-part breakdown, and personalized tips for improvement.

Think of it as a personal plank coach you built yourself — and once it works for planks, you can expand the same system to push-ups, yoga poses, or even running form.

Tools We’re Using

• Lovable → Builds the front-end interface (fast, pretty, AI-powered)

• Momen → Handles the logic, AI agents, and backend

• Vibe Architect → Bridges the two with a ready-to-use prompt

Why this combo?

• Lovable is fantastic for front-ends, but for AI agents and data, it usually asks you to wire up Supabase — great if you code, not so fun if you don’t.

• That’s where Momen comes in. It’s a full-stack visual builder, so you can set up AI agents, databases, and workflows without touching code.

• Vibe Architect glues them together by turning your Momen AI setup into a plug-and-play prompt for Lovable.

Step-by-Step: Build Your Plank Coach

Step 1: Define Your Concept & Prepare Data

Before you build anything, map out what the app should actually do. In our case, the goal is simple: give users clear, actionable feedback on their plank form.

• Product Logic Flow (MVP case):

  1. User uploads a short plank video.

  2. The system processes the video and detects body alignment.

  3. The AI compares this posture against a “plank playbook” (proper form + common mistakes).

  4. The AI outputs structured feedback: an overall score, body-part breakdown, and improvement tips.

  5. The front-end (built in Lovable) displays the results in a clean, easy-to-read way.

• Reference Data: To make this work, collect “plank playbooks” — posture guidelines, examples of good vs. bad form, and correction tips. This ensures your AI agent isn’t just guessing but is anchored in real fitness knowledge.

• Data Setup in Momen: Momen already includes default tables like accounts and ai_messages. For this app, you just add a couple of simple tables. You can either create them yourself or import them directly in Momen:

  • plank_guidance — proper form guidelines and tips.

  • plank_playbook — common mistakes and how to fix them.

  This structure gives your AI agent a clear knowledge base to draw from when analyzing each video.

Step 2: Build the AI Agent in Momen

• Database: Use the tables to store exercise knowledge.

• Agent Config:

  • Input: Video

  • Define Prompt:

    • Role: Professional fitness coach

    • Goal: Detect alignment, spot weaknesses, suggest fixes

    • Context: Pulls from your plank database for accuracy

  • Output: Structured results (e.g., core, arms, hips) with clear tips

    
    

💡 Use debug in the right side of Momen AI to test and tweak until the agent gives solid, specific feedback.

Step 3: Connect to Lovable with Vibe Architect

• In Momen, open your AI agent and copy the AI Blueprint (from the top-right menu).

  
  

• Head to Vibe Architect and paste it in. Click “Covert”

  
  

• Go to Lovable, create a new app, paste the generated prompt, and watch Lovable spin up your front-end.

  
  

📌 That’s it — your Momen brain now talks to your Lovable app.

Key Takeaways

• You don’t need to be a programmer to build a powerful AI fitness tool.

• Momen takes care of the backend: agents, data, workflows.

• Lovable makes the UI fast, intuitive, and polished.

• Structured outputs keep feedback clear and actionable.

• You can expand beyond planks — think push-ups, yoga, or even running gait analysis.

Try It Yourself

• 🎥 Live Demo: Plank Analysis in Lovable

• 🛠️ Explore Vibe Architect: Try it here

• 📋 Copy AI Agent Blueprint: [Momen Editor link]

Build once, learn a lot, and suddenly you’ve got an AI coach in your pocket.