HackNYU 2025 · Interactive Media Track Winner

ZenPose

AI-powered real-time pose feedback for safer, smarter yoga.

My role
Co-creator · frontend, pose evaluation, Gemini integration
Team
Yaashna Gupta · Jennifer Zhu · Russel Sy
Built with
BlazePose · React · Gemini API · Custom pose evaluation
Time
24 hours, HackNYU 2025
A presenter holds a wide-stance yoga pose on stage at the MLH AI Roadshow. Behind her, the projected ZenPose screen shows a reference photo of the pose, the live camera feed with her body tracked, and a progress bar.

Live demo · MLH AI Roadshow, NYC

01

The Problem

Zoom workouts and online yoga are everywhere. They remove the one person who’d normally watch and correct your form.

  1. You follow an online yoga class or workout.
  2. You perform a pose.
  3. No instructor is there to correct you.
  4. Your form may be off, and you don’t know.
  5. Small misalignments repeat, and can add up to long-term injury.

What if AI could guide your form like a yoga coach?

02

The Idea

ZenPose is a web app for safer, smarter yoga.

A camera watches your pose. The system checks your form, waits until you’re steady, and gives you feedback straight away. Get it right and you earn a point, plus a snapshot of the moment.

ZenPose lotus mark
  1. You hold a pose
  2. ZenPose tracks your body
  3. It checks your form
  4. It waits for a steady pose
  5. You get feedback
  6. Correct: a point + a snapshot
03

The Experience

A presenter holds a wide-stance yoga pose on stage at the MLH AI Roadshow. Behind her, the projected ZenPose screen shows a reference photo of the pose, the live camera feed with her body tracked, and a progress bar.
  1. The target. A reference photo of the pose to match.
  2. You, tracked. The live camera feed with your body’s joints followed.
  3. Progress. A bar fills as you hold the pose, with a running score.
  1. Pose

    You take the pose shown in the reference photo.

    Reference image
  2. Detect

    The camera feed becomes a set of tracked joints.

    BlazePose
  3. Evaluate

    Joint angles are compared with the reference, relative to your hips.

    Custom math
  4. Stabilize

    A buffer waits for a steady pose before anything is scored.

    Smoothing buffer
  5. Feedback

    A point and a snapshot for a correct pose, plus encouragement or an adjustment.

    Gemini API
ZenPose start screen: the lotus mark, the line 'Test your yoga skills! Complete as many yoga poses as possible in one minute', and a Start Game button

The start screen frames it as a one-minute challenge.

04

Making computer vision behave like a usable product

The model could find a body. It couldn’t reliably tell whether your body was right. Pose detection misclassified people because everyone stands, and is built, differently.

One pose, three bodies. Against a fixed reference, each is “wrong” in a different way.

Illustration of the approach, not recorded data. Dashed = reference pose.

  1. Started withFixed-position model

    Compared people to a reference at fixed coordinates. It didn’t generalize across users.

  2. ThenHip-anchored positioning

    Re-centered each pose on the person’s own hips, so position in the frame stopped mattering.

  3. ThenRelative joint angles

    Judged the relationships between joints rather than absolute coordinates.

  4. FinallyStability buffer

    Only scored steady poses, which smoothed out flicker between frames.

For feedback to feel trustworthy, the technology had to be reliable first. That was the real design problem.

05

The AI Experience

Not “lots of AI”. Three different jobs, each handing off to the next, in a loop with the person at the centre.

  1. YouMovement

    You hold the pose.

  2. BlazePoseComputer vision

    Finds your joints in the camera image.

  3. Custom mathEvaluation

    Are the angles right, and is the pose steady?

  4. Gemini APIAI feedback

    Compares with a reference image and answers in plain language.

  5. YouResponse

    Encouragement, or an adjustment to try.

↺ And back into the next attempt

Sees

Computer vision identifies what you’re doing.

Decides

Custom evaluation determines whether the pose is correct and stable.

Says

Generative AI turns that result into feedback a person can act on.

06

Rapid Prototyping

24Hours to build it
~3Hours of sleep
Day-ofTeam formed at the hackathon
The team at their table at HackNYU: one teammate waving at the camera in a selfie, two more working behind her, with laptops and food on the table
The team, mid-hackathon
An early prototype on a laptop: a page titled Yoga Pose Detector showing a webcam feed beside a plot of red body-keypoint dots
An early prototype: just the tracked points, beside the camera

Looking back, what the constraint pushed us toward

  • Get the core loop working first: a pose in, feedback out.
  • Spend attention on the hardest problem we hit, reliable detection.
  • Use existing tools, a pre-trained pose model and a hosted AI model, instead of building from scratch.
  • Even use AI to generate reference pose data, to keep moving.
  • Keep one clear experience: hold a pose, get feedback, earn a point.
07

Presented live

1 of 3teams selected to demo live at the MLH AI Roadshow in NYC

A presenter holds a wide-stance yoga pose on stage at the MLH AI Roadshow. Behind her, the projected ZenPose screen shows a reference photo of the pose, the live camera feed with her body tracked, and a progress bar.
MLH Roadshow · HackNYU 2025

After building ZenPose at HackNYU, we presented the project through the MLH Roadshow, demonstrating the AI-driven pose feedback system live. We were selected out of thousands of Gemini-powered hacks to be one of three teams to demo on stage.

A presenter in a half-moon pose in front of the projected ZenPose screen, which shows the reference pose and her live camera view; her co-presenter holds a microphone to the left
08

Result

Interactive Media Track Winner

HackNYU 2025

  • Invited by Major League Hacking to present at the MLH AI Roadshow in NYC.From the original post
  • One of three teams selected to demo live, out of thousands of Gemini-powered hacks.From the original post
  • Detection accuracy improved by 40%.From my resume
  • Our first hackathon, and a working product at the end of it.HackNYU 2025
09

What we learned

AI wasn’t just part of the product. It became part of the way we built it.

  • Learning on the job

    None of us had worked with AI before. We learned the tools by building with them.

  • AI as a collaborator

    It helped us learn, debug and build faster, and even generate reference pose data.

  • Judgment stays human

    We used AI to amplify our decisions about the experience, not to replace them.

You don’t need to be an expert to build something real.From our presentation
10

What’s next

Directions we’ve talked about. None of these are built yet.

  • More yoga poses
  • Customizable routines
  • Personalized feedback over time
  • Real-time voice coaching
  • Continued improvements to detection