AI Video Diagnosis of Your Movement Pattern: startup idea with real demand
One person can't do a lunge in any variation after a hundred tutorials; another hasn't activated their left glute in Bulgarian split squats for a year. Generic tutorials don't fix their case.
r/xxfitness · Sep 14, 2026 – Oct 14, 2026 · 60 upvotes
Unable to do lunges. At all
Read the thread · 84 comments
AI Video Diagnosis of Your Movement Pattern is a startup idea for gym-goers and people who train at home. One person can't do a lunge in any variation after a hundred tutorials; another hasn't activated their left glute in Bulgarian split squats for a year. Generic tutorials don't fix their case. A thread in r/xxfitness drew 60 upvotes and 84 comments between Sep 14, 2026 – Oct 14, 2026. People get by with Online coaches and Form-check subreddits, and that still leaves this job open. Hotness is 3.10, Warm. Real but moderate pain. Some willingness to pay. The thread drew 60 upvotes and 84 comments. Gaps in existing tools. Needs integrations or data deals. A first version is a hard build, about 5+ weeks, priced between $10 and $49 a month and charged as a subscription. The pain, the source, the alternatives, the scope notes, and the questions on this page are free to read and free to build from. The agent starter prompt is the paid part. The first slice is on the page. One credit unlocks the rest, to paste into a coding agent, download as Markdown, or send as a private link.
Verbatim quotes are added only after a manual check. Until then, the thread title is the excerpt. Exact post date and verbatim quotes pending enrichment.
Who has it
Gym-goers and people who train at home.
What people use now
- Online coaches
- Form-check subreddits
A way through
An app where users upload video of a movement and AI pinpoints the asymmetry or compensation in their body, with targeted corrective exercises.
MVP scope
- Give gym-goers and people who train at home a way to do this in one sitting: Upload a clip of your lunge or split squat and get told which compensation your body makes, plus targeted fixes.
- Persist the result and show it again after a reload.
- State the empty case when there is nothing to show yet, with one next step.
- Charge later with a subscription, between $10 and $49 a month. The free path must finish the core job once.
- Ship the mobile app only. Leave Online coaches to keep the jobs they already do well.
How it could charge
Subscription · $10–49 a month · B2C · GLOBAL.
Hotness 3.10
3 of 5, Warm. Real but moderate pain. Some willingness to pay. The thread drew 60 upvotes and 84 comments. Gaps in existing tools. Needs integrations or data deals.
Why this score
| Pain | 3 / 5 |
| Willingness to pay | 3 / 5 |
| Demand | 3 / 5 |
| Competition gap | 3 / 5 |
| Ease of build | 2 / 5 |
| Recency | 5 / 5 |
Weights: pain 25%, willingness to pay 20%, demand 20%, gap 15%, ease 10%, recency 10%. Recency is recomputed every build. The source report’s 1–10 score is not shown.
Questions
Is this idea already taken?
People already use Online coaches, Form-check subreddits. Those options do not do the job in the solution above. The idea is free to build. Nothing here is an exclusive claim.
How hard is a first version?
Hard. A tight MVP is about 6 weeks (5+ weeks), assuming the regulated or partner-gated parts are stubbed. The paid prompt turns that into tasks.
Who would pay, and how?
The audience is gym-goers and people who train at home. Charge a subscription, and test a price between $10 and $49 a month. Willingness to pay is one input to Hotness, not a promise that someone will buy.
Can I use the evidence?
Yes. Build the product. The thread title is a short excerpt with a link, not a quote we are putting in someone's mouth. Exact post dates and verbatim lines are added only after a manual check. Ideas are suggestions, not medical, legal, or financial advice.
Agent prompt
The first slice is public. The rest is fetched only after you unlock it, and it is not in this page’s HTML.
# Agent starter prompt: AI Video Diagnosis of Your Movement Pattern You are a senior product engineer. Build only the product described in this document. If a detail is missing, choose the smallest option and write it down in the README. Do not invent a second product, a marketplace of marketplaces, or a growth hack. ## Product Name: AI Video Diagnosis of Your Movement Pattern One line: Upload a clip of your lunge or split squat and get told which compensation your body makes, plus targeted fixes. Shape: Mobile app AI stance: AI-native Region for v1: Global Hotness (context only, not a requirement): 3.10 (warm). Real but moderate pain; some willingness to pay; thread engagement 60▲/84💬 (demand 3/5); gaps in existing tools; needs integrations or data deals. ## Problem One person can't do a lunge in any variation after a hundred tutorials; another hasn't activated their left glute in Bulgarian split squats for a year. Generic tutorials don't fix their case. Who feels it: Gym-goers and people who train at home.
Unlock the rest with 1 credit.
The sister site keeps a free plan and a free growth prompt for the same pain. The business-plan version
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