Sensor-based Strength Training Tracking System

Multi-Sensor Tracking Real-Time Feedback Fitness

Problem: Manual logging limits real-time feedback and data-driven strength training.

Solution: Multi-sensor strength training devices for pin-loaded and plate-loaded machines integrated with a mobile app for real-time monitoring and feedback.

Project cover image

Background

Digital Healthcare Demand Is Increasing

Keyword search trends ⬆︎ and market growth projections ⬆︎

Data-Driven Aerobic Tracking Services Are Expanding

Mobile tracking adoption ⬆︎ and user engagement & satisfaction ⬆︎

Lack of Data-Driven Strength Training Tracking

No automated or quantitative measurement of strength training performance


User Research

Painpoints

  • Manual logging is time-consuming and often inaccurate
  • Workout data is scattered and difficult to manage
  • In-exercise performance cannot be checked in real time
  • Correct exercise form is difficult to learn and maintain

Needs

  • Automated tracking of workout performance
  • Structured data management for consistent workout records
  • Real-time feedback during exercise
  • Exercise guidance for correct execution

Goal

Context

  • Gym
  • Home

Users

  • Strength training users
  • Gym managers

Tasks

  • Tracking
  • Analysis
  • Feedback

" Design an integrated system for measuring, analyzing, and providing feedback on strength training performance "


Key Challenges

Accurate sensing across heterogeneous machine structures

Linear and rotational motion patterns require different sensing approaches

Real-time measurement–analysis–feedback loop

Low-latency processing is required to deliver immediate feedback during exercise

Seamless hardware–mobile interaction

Instant and seamless connectivity is needed to avoid disrupting workout flow


User Scenario

Connect

NFC-based pairing

Measure

Multi-sensor tracking

Feedback

Real-time performance

Coaching

Trainer monitoring

Analysis

Workout data insights


Solutions

S1. Accurate & Deployable Measurement

  • Pin-Loaded machine sensing: Infrared Sensor (motion detection), Time-of-Flight (ToF; distance & weight estimation)
  • Plate-Loaded machine sensing: Gyroscope (rotational motion detection), Load Cell (force & weight measurement)
  • Detachable & attachable hardware design
  • Compatible with existing equipment
Measurement device attached to a pin-loaded machine

Fig.1. Measurement device attached to a pin-loaded machine

Measurement device attached to a plate-loaded machine

Fig.2. Measurement device attached to a plate-loaded machine

S2. Real-Time Connected Training System

  • Sensor → MCU → Bluetooth → Mobile App
  • Real-time performance feedback (speed, reps)
  • NFC-based one-tap interaction
  • User–Trainer integrated UX
System components: pin-loaded device, plate-loaded device, NFC-enabled smartphone dock, and mobile application

Fig.3. System components (devices, NFC dock, mobile app)

Internal design of the pin-loaded and plate-loaded devices with NFC-enabled dock

Fig.4. Internal design of devices and NFC dock


Results

  • Multi-machine tracking system (pin-loaded & plate-loaded)
  • End-to-end prototype (sensor → app pipeline)
  • Real-time feedback for performance improvement
  • Data-driven training & coaching workflow
Final prototype

Fig.6. Final prototype

Fig.7. Motion measurement process for the pin-loaded machine

Fig.8. Motion measurement process for the plate-loaded machine