Real-time form correction for safer solo weightlifting
My role
Product Designer
UX Researcher
Team
Lin, Advisor
Brodowski, Advisor
Timeline
16 weeks
Parsons School of Design
Major Studio 2
Area
Mobile App
Project Overview
Problem
Casual weightlifters often lift alone, with no one to warn them if their form is incorrect, putting them at risk of hurting themselves. With a lack of guidance, poor positioning can lead them to execute moves incorrectly while increasing the weight carried, leading to serious injury.
Solution
A weightlifting-focused mobile app using AI-driven human pose estimation technology to "spot" form. As users film themselves lifting, the app analyzes their execution in real time and provides alerts to correct their form, which optimizes workouts and prevents injury.
Impact
I led the research and spoke with over 10 weightlifters to uncover key pain points and opportunities. From there, I shaped the MVP around their real lifting experiences, iterating on designs that actually made sense for them. I built a full design system and brought the product to life with a high-fidelity prototype— driving the entire process from insights to execution.
The problem
Incorrect form when weightlifting can lead to serious injury.
There's no significant association between injury occurrence and gender, age, or body mass index. However, there is a significant association between injury occurrence and weight carried while lifting weights. Since casual lifters struggle to correct their form when lifting alone but continue increasing the weight carried, they risk serious injury.
Why is this problem important?
1 in 4
People reported doing weight-lifting activities weekly in the US, integrated into their routine.
CDC, 2022
94%
Increase in interest in strength training classes since 2022- and it's still growing!
CNN, 2023
61%
Of weightlifting injuries are due to technical errors, not gender or age like some might think.
CBI Insight, 2018
The design challenge
How might we teach casual weight lifters proper form during their sets to optimize their workouts and prevent injury?
Research & User Interviews
What is the current weightlifting experience?
To create a solution that would really help people, I first wanted to understand the current lifting experience. I conducted 7 preliminary interviews with a wide range of users, from beginners (< 1 year) to veterans (10+ years) and those who don't use any tech to power users. Based on my insights, I identified 3 key pain points which informed my ideation process.
Follows Online Programs or Workout Videos
Creating a workout routine on your own can feel intimidating— most people don’t see themselves as experts when it comes to knowing exactly what to do to get the results they want. That’s why many turn to fitness apps or online workout videos instead.
"Instead of trying to come up with my own routine, I decided to try and see if the fitness watch program can actually get someone who doesn't work out at all to become active."
Nicole, newbie + loves apps
70% of active adults watch videos to support their exercise regiment.
run repeat
Would Prefer Coaching, But Trainers Are Too Expensive
Watching videos or reading about form isn’t as effective or as safe as getting real-time feedback while you’re lifting. Most users weren’t ready to invest in a personal trainer, especially when they were just starting out and unsure if they'd stick with it.
"The biggest point is that since I don't have a trainer, there's no one who's gonna correct me. But I wouldn't know if no one actually teaches me."
dennis, long time + loves apps
1-on-1 training effectively changes attitudes and increases physical activity.
liberty of medicine
Incorrect Form Has Caused Injuries
It's important to push yourself in any sport in order to improve. However, when weightlifters keep increasing their weight carried while continuing to do the exercise incorrectly, it can actually halt their progress or in worse cases lead to serious injuries.
"I was doing a deadlift, and the posture wasn't right, and I was alone at the gym without a trainer as well, and I really hurt my back."
SHAURYA, long time + LOVES apps
Inaccurate posture increases injury risk and doesn’t target the correct muscle groups.
adaptiv
user personas
I created two user personas to guide my ideation process: one who just started weightlifting and another who is an experienced lifter.
Lifting Newbie
Weightlifting 3 months
Behaviors
Just began lifting and following fitness influencer workout videos. They worry about getting hurt when trying a new set but find the personal trainers too expensive to start off with.
Goals
To get personalized guidance during workouts to make sure their form is correct and prevent injury.
Dedicated Learner
Weightlifting 5+ years
Behaviors
Working out is an essential part of their routine. They started researching proper form after a serious injury, not realizing they'd been doing the exercise incorrectly the whole time.
Goals
To consistently improve their form and see results, like a new 'personal best' in weight carried.
narrowing the scope
Could we 'spot' weightlifters digitally?
'Spotting' in weight training is supporting the person lifting. Spotters help the athlete complete the lift, ensure proper technique, and prevent injury. They also boost an athlete’s confidence level and morale, leading to better performance during their workout.
Human pose estimation (HPE) for corrective feedback gets the most attention in AI fitness applications since it can analyze the movement of athletes in different scenarios using just a smartphone camera.
user journey
I mapped out the current user journey for completing a set and pinpointed key moments where the app could step in to help prevent injury and support better form.
Development
Turning key insights into main features
The success metrics below focus on concerns gathered during interviews and inform the key features to be explored.
Lack of 1-on-1 Instruction -> HPE-Driven Form Analysis
Do users want to choose when they're tracked, or would that be the default?
Risk of Injury -> Correctional Alerts
How much information on form analysis would be most helpful for users, and when?
Proof of Progress -> Personalized Tracking
Will users want to compare the day's workout results with their progress history?
Sketching
I started by sketching out different screens based on insights from my interviewees, including coach-led workout routines, form analysis and corrections, and post-workout analysis.
Home Page, Weekly Progress
Workout Video
Human Pose Estimation Tracking
Post-Workout Analysis
Mid-Fidelity Prototype
Based on user insights and my brainstorming, I designed prototypes for 2 divergent concepts to test with users and get their reactions on what resonated with them and what didn't.
Concept 1: Live Feedback & Timers
This concept involves users toggling between coach-led videos and Spot Me analysis mode for live feedback. Alert information is bite-sized and given in real time so that users can quickly correct their execution.
Concept 2: Delayed Feedback & In-Depth Analysis
This concept involves users recording themselves, completing the set, and then submitting the video for in-depth feedback. They're able to see all the alerts at once.
user testing
By testing these concepts with casual weightlifters who have struggled with their form, I was able to notice patterns when it came to how features would integrate into their lifting routines.
Quality Over Speed
Timer and progress bars weren't needed since users focus on the quality of each rep rather than how quickly they can finish a set.
Quick Alerts Now
Further information is useful in post-analysis but during the workout quick, bite-size alerts on what to correct are more important.
Progress Tracking
Users were curious to see how this workout’s accuracy compared to past ones also logged into the app.
The Solution
Spot Me helps casual weightlifters safely train solo by using human pose estimation to provide real-time form corrections.
Coach-Led Workout Videos
Easily track this week's progress, motivating you to keep up the hustle. Workout cards and coach-led video tutorials make it easy to follow along each set and alleviate the stress of routine planning.
Final design
Design decision
Focus on Quality Over Speed
mid-fi design
Timer and Progress Bar
Lifters prioritize quality over speed, so time indicating UI is unnecessary. Rather than taking videos, users prefer live analysis.
solution
Remove Timers, Emphasize Rep
Highlight exercise names, reps, and weights instead. Toggle easily switches between modes for feedback.
Form Analysis and Corrections
Easily toggle between coach-led video and 'Spot Me' pose tracking mode. Incorrect form triggers bite-size audio and visual alerts- as a coach would! Modals disappear once the form has been safely corrected.
Final design
Instructional Video
Real-Time Form Feedback
Design decision
Alerts in Real-Time
mid-fi design
Lengthy Feedback
Need live feedback for immediate correction. Alert size and text were too small to read from afar. Further information is more helpful post-workout.
solution
Bite-size, Real-time Alerts
Form alerts are large, simple, and audible. Fullscreen modal to capture the user's attention. An in-depth form analysis is given post-workout.
Post-Workout Analysis
End the workout with a brief performance recap and an option for detailed information on each set. See all alerts to see your mistakes and learn how to improve.
Final design
Post-Workout Analysis
Accuracy of All Workout Sets
In-Depth Analysis of a Set
Design decision
Personalized Progress Tracking
mid-fi design
Surface Level Achievements
Stats are too general- users want a set-by-set accuracy breakdown of the entire workout.
solution
In-Depth Insights Into Workout
Show progress over week, month, and year. Highlight improvements in accuracy, alerts, and weights lifted.
Final design
Alerts Detected
Accuracy, Alerts, and Weights Carried Over Time
Reflections
What did I learn from this project?
Design Isn't a Linear Process
At the start of this project, I was uncertain about which fitness problem to tackle. It wasn’t until my mid-fidelity interviews that I focused on weightlifting. The process involved revisiting my research, but that’s the thrill of design— drawing, researching, testing, and repeating. Keeping the user’s needs as my north star guided me to a genuine area of opportunity.
It's Important to Stay Curious
I love getting into UI and UX design, but that’s just one piece of the puzzle. Researching AI has shown me how crucial it is to stay updated with the latest tech to keep innovating. I think it’s all about balancing the tech we have with imagining what it could be to keep pushing the boundaries.
