Show HN: Workout.cool – Open-source fitness coaching platform (github.com)
Over the next 9 months, I sent 15 emails to try to save it : no replies. Feature requests & issues were ignored. The community was left with a "broken" tool let's say.
I couldn't just let it die So I built the new version from scratch with the same open-source spirit, but a better architecture long-term vision, more features and no license problems.
It's called : Workout.cool (https://workout.cool). What it offers: 100% open-source, MIT-licensed - 1200+ exercises (with videos, attributes, translations) - Progress tracking - Multilingual-ready - Self-hostable
I'm not doing this for money. I'm doing it because I believe in open fitness tools, and I’ve been passionate about strength training for 15+ years.
If this resonates with you, feel free to: - Star the repo - Share with fitness/tech friends - Suggest features - Contribute code/design/docs
Together, we can build the open-source fitness platform we all wanted to easily build a workout routine and get in shape
Website: https://workout.cool GitHub: https://github.com/Snouzy/workout-cool
247 comments
[ 3.4 ms ] story [ 235 ms ] threadYes, sharing workouts is on the roadmap. Users will be able to create routines, save them, and share them with others (even with public links) as the previous workout-lol project.
As for API integrations (Strava, Garmin, HealthKit, etc.) definitely something I’m open to.
Curious to know : what kind of data would you want to sync or pull in? Workouts? Step counts? Heart rate zones?
Think of it similar to the Strong app, but aimed at trainers/PTs.
https://www.medbridge.com/care/home-exercise-program
has muscle selection is so much more help full than 80+% apps on app store right now
With that said, the website works just fine on my phone.
I retrieve error response when fetching exercise:
0:{"a":"$@1","f":"","b":"eETmgndxtv4Ar0i8Wync1"} 1:{"serverError":"An unexpected error occurred."}
My request: curl 'https://workout.cool/' \ -H 'accept: text/x-component' \ -H 'accept-language: en-US,en;q=0.9,pl-PL;q=0.8,pl;q=0.7' \ -H 'cache-control: no-cache' \ -H 'content-type: text/plain;charset=UTF-8' \ -b 'Next-Locale=en; _fbp=fb.1.1750253718188.954698194752805529' \ -H 'next-action: 7f80b017f78704b00d2411aebde5ba8318b475de6d' \ -H 'next-router-state-tree: %5B%22%22%2C%7B%22children%22%3A%5B%5B%22locale%22%2C%22en%22%2C%22d%22%5D%2C%7B%22children%22%3A%5B%22__PAGE__%22%2C%7B%7D%2C%22%2F%22%2C%22refresh%22%5D%7D%2Cnull%2Cnull%2Ctrue%5D%7D%5D' \ -H 'origin: https://workout.cool' \ -H 'pragma: no-cache' \ -H 'priority: u=1, i' \ -H 'referer: https://workout.cool/' \ -H 'sec-ch-ua: "Google Chrome";v="137", "Chromium";v="137", "Not/A)Brand";v="24"' \ -H 'sec-ch-ua-mobile: ?1' \ -H 'sec-ch-ua-platform: "Android"' \ -H 'sec-fetch-dest: empty' \ -H 'sec-fetch-mode: cors' \ -H 'sec-fetch-site: same-origin' \ -H 'user-agent: Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Mobile Safari/537.36' \ --data-raw '[{"equipment":["PULLUP_BAR","BANDS","BODY_ONLY"],"muscles":["TRAPS","BACK","SHOULDERS","TRICEPS","FOREARMS","GLUTES","HAMSTRINGS","CALVES"],"limit":3}]'
I’m working on stabilizing it and will have a fix in the next minutes / hour
Appreciate you testing it out! thanks again.
Selected a few workouts and got this error - Error loading exercises. I'll try again after a few hours. Congratulations on the launch!!
The issue should be fixed RN !
Definitely feeling the HN kiss of traffic right now lol, Ii’m scaling things up and fixing the bottlenecks
Really appreciate you trying it out.
And yes seems like the HN crowd is more health-conscious than I thought. Loooove it !
Thanks again for the kind words and support!
The main problem with any app I've tried is that after enough experience the bells and whistles of the app don't really matter and mostly what you care about is consistent tracking for progressive overload.
I think this is a good app for people who want to get started weightlifting I would say the two main things needed for wider adoption would be 1. A mobile app ( or pwa, I've made and used my own personal workout app for a while as a PWA and its been just as good as any native app I've tried) 2. A way to save specific workouts as routines and track those for long periods of time
Why are compound lifts in the middle of the workout and why am I doing three different types of chin ups? There are also no reps / sets calculated nor are there 1RM percentages for weight.
Bro splits are some of the lowest quality routines you can use and this somehow makes them worse. You could replace all of this, remove the bells and whistles, and create a bare bones PPL app that determines exercises based on equipment available and it would be light years better than this.
I got the feeling they were more options and you could reorder them if you wanted or shuffle or just do one or another.
To me a more casual / getting started is just about doing the thing.
Beginners should be focusing on form and simple compound lifts. Throwing them into things like heavy accessory lifts with no regard for exercise choice or format is a quick way to get hurt. Again, I want to applaud OP for doing this. The fitness industry is in a terrible place and tools like this have a great place. I just think it needs a ton of work to make it useful. Maybe if I find some time, I'll try and contribute but in it's current state I would never recommend something like this to anyone.
The phone appears to be a distraction for many people I watch at the gym, over-extending the rest between sets while watching social media. The minimalism provided by the paper notebook is what I prefer instead.
* Not enough volume
* Non-periodized
That first bit means different things at different phases of a lifting "career". But generally speaking "time under tension" and research into effective rep ranges has changed modern thinking on set sizes and volume.
These days people, including World's Strongest Men, tend to recommend higher rep ranges for beginners and those coming back to the gym to build work capacity and reduce risk of injury.
For reference, I went from a dumbbell bench press of 45lb to 75lb in 4.5 months (5x5). Previously my progress was much slower.
I'll caveat that I've obviously not closely controlled for all factors and I'm an n of 1. Additionally my interest is in having a great strength to weight ratio, rather than being a body builder. I'm a climber and that's an important consideration.
Progressive overload works. Those programs "work".
They are just out of vogue for beginners, and they are both targeted towards beginners.
You have been lifting weights somewhat regularly for 25 years, majority 3x8-12, and the switch to 5x5 increased your dumb bell bench press from ~20kg to ~35kg?
There is just no way. That is extremely light weight. Like, most beginners who follow any sort of progressive overloading system will be at that level in 4 weeks starting from essentially 0
after 15 years of lifting, I'm currently pushing 4x10 with 50kg dumbbells on the bench. So yeah, 35kg after 25 years seems odd unless those 25 years weren't exactly "serious" or "consistent" let's say.
No judgment, but yeah
That's why I recommend keeping it simple. Build the habit and build some strength. Once you've done that, you can get fancy if you find that you're really into it.
What are your goals?
But I do agree with your assessment. Each exercise needs a categorization (compound, isolation), compliments (if an exercise is a push, then what are some pulls), companions (if you're working arms at the cable stack, might as well do a bunch of arm/shoulder/back cable exercises), and a est. time to perform (including warmup, setup). This will allow plans to be generated in a way that makes sense.
Though, I think community made exercise plans are a better solution than trying to devise algorithms to generate good plans. Though, an LLM integration might work well for beginners, send a prompt with a list of exercises and goals (i.e., beginner looking for a 3 day a week strength plan, build one using these 20 exercises).
Btw I totally agree: once you’ve been training a while, the only thing that really matters is tracking your progress and showing up consistently (or "mental" side in my case, i do not train anymore for performances).
Good news : saving + tracking routines over time is in the roadmap.
That's why the architecture of the "workout session" is the part that is the most different from the old app.
I want users to create, reuse, share, analyse and evolve their own training blocks with minimal friction.
Would love to hear how you handled that in your own PWA sounds like we've walked similar paths :)
https://json-schema.app/view/%23?url=https%3A%2F%2Fgist.gith...
Are there really no open licensed workout-movement animations out there? That sounds like a fun beginner animation project honestly.
I wanted to make sure everything is legally safe and not just scraped or reused without rights.
Producing proper 3D exercise videos is actually VERY expensive we’re talking €10–20 per animation, or thousands of euros per month if you go through a good/high quality API provider. That’s why it's such a tough space for open-source tools to compete in.
Long-term, I'd love to help build a community-driven, open-licensed library of movement animations but until then, this partnership was the best balance between cost, legality, and quality.
Thanks for raising it
Bcs a lot of beginners don’t know what to do with certain equipment, but they do know what they want to train.
That said, I’ll maybe make both paths easier and let users toggle between them!
PR ares welcome
What are your thoughts about the wger project [0]? It is a FLOSS AGPL-licensed self-hosted fitness/workout/nutrition manager that has existed for almost a decade (I think?) It's a django app and has a companion flutter app that runs on android/ios/windows/linux/macos. It supports multiple users and could even be used to run a gym. Body.build [1] is a newer FLOSS project (also browser-based) that is focused around building a weight lifting program. The author of body.build also contributes to wger.
I'm using wger in my homelab and while there are a lot of moving pieces to the self-host process, it works well. I'd say the biggest limitation is the comprehensiveness of their exercise database, but that is something that many people have recognized and are steadily expanding. If anyone is willing to contribute exercises (and exercise media) to this AGPL licensed project, they would definitely appreciate it!
[0]: https://github.com/wger-project
[1]: https://github.com/Dieterbe/body.build
Traffic spiked and my backend rate limits kicked in too hard.
Thanks so much for trying it out
Everything should be back to normal now
Really appreciate your patience and thanks again for giving the app a try and sorry again guys.
It's interesting that fitness and weightlifting are pretty common these days, but there are so few non-commercial applications out there that are usable and well maintained. At least that's my perception after digging through dozens of Github projects.
As someone who doesn't know much about working out or what exercises to do this sounds like a good app. I need help, but picking based on muscles is off. My thought and goals are not by muscle group, but losing weight or getting more toned.
Conversely, someone who knows what muscle groups they want to target, probably already has some sense of the exercises to target and thus less likely to need the app.
Also - for most people who had accidents they'd probably rather click on "Dislocated Kneecap" and then have the software suggest exercises to help with that condition - vs needing to bring that knowledge to the app.
The goal is to make the app more welcoming by offering goal-based (or filters,let's see) entry points like "fat loss" "beginner full-body" or "3x/week routine" and not require anatomy knowledge to get started.
The muscle filter will just be one of many ways to browse, not a gatekeeper i guess. Thanks a lot for highlighting this!
Personally, as someone that exercises but not for aesthetics, I think of strength training in terms of movements not muscles worked. So I'm thinking "press, pull, squat, hinge" not "chest, lats, glutes". Thinking of function and then doing fundamental compound movements just makes more sense to me, although I do sometimes need to hone in on a muscle for functional reasons -- like targeting the glute medius for opening up my kicks in my Muay Thai training.
Neither is more correct, they're just different approaches.
I’d love to see your ideas make it into Workout.cool!!
Let me know if you need help porting the PRs îll support and merge contributions quickly.
For example as a heavy FB Market place user I see a lot of stuff like:
[picture of an iPhone 12]
- iphone 14 - new battery - delivers to [enter your state here] - comes with [enter accessories it comes with]
Like they were too lazy to even fill in the brackets or ensure some level of accuracy. What's the point?
For most people a pull up bar plus body weight exercises will get them everything they want: enough fitness for good health. If you want to win competitions you need the right equipment (different competitions need different equipment).
I'm already planning to make the filters optional, and add things like "beginner-friendly", "popular exercises", "calisthetics", ...
Thanks for pointing it out
lol true
Tbh that's exactly the gap Im trying to fill with Workout.cool. After reading all the feedback here (including yours), I've realized we need to make things even simpler and more beginner-friendly.
not some hyper-optimized tracker, but yeah a simple, open, and welcoming entry point into strength training. Got it. It's faaaar from perfect yet, but it's made with that intention at heart. Trust me !
Thanks again for your feedback mate.
But that is the person who will use and pay for the app. If spending $100 will get them a training plan that is 0.01% better they will do it. Couch potatoes know they need to change, but they probably won't pay for a app (if they do they won't use it).
sent 15 emails over 9 months to the new owner, offering to help or even take over the repo but i had no replies.
Issues and PRs were ignored(you juste have to see the issues section of the report). Rebuilding from scratch was the only way to fix the licensing & continue the project i guess
And what specifically were the licensing issues? workout.lol is MIT from what I can see.
The licensing issue I referred to was about the videos: many of them came from paid/licensed sources
I wanted to move to a more "new", (robust?) and maintainable stack with TypeScript and a SQL-based backend (PostgreSQL)
Copyleft licenses like the GPL come with extra guarantees that do not violate the core guarantees of open source software. Instead, they make them stronger. The 'restrictions' GPL imposes essentially boil down to this: "if you use (parts of) GPL software, you must give your users the same freedoms the GPL guarantees." GPLv3 and AGPL closed up loopholes that allowed people to bypass those clauses.
[1] https://opensource.org/osd
But in this case the original project used the MIT license, so the only requirement is that it the form includes attribution to the original project.
- https://wrkout.xyz/ (exercise database api with images and videos) - https://github.com/wrkout/exercises.json (open source exercise dataset)
If they are of any interest / help
For this, i rebuilt the entire dataset from scratch with a partner to avoid any licensing ambiguity (especially with videos), and to have full control over attributes, translations, etc.
But I absolutely love seeing other open projects in this space and I'd be happy to explore possible synergies if it can help both communities.
DMs open !
I'm looking forward to Meta adding this feature to their Ray Ban smartglasses so the glasses automagically count my calories each time it sees food on my plate or going into my mouth. A feature they possibly should make optional, but for me who has prescription Metas it would be a big time saver (try to eat 1500 to 2000 calories a day and burn 250 to 500 in exercise). I think the knowledge of how many calories you consume done automagically would prompt 1/4 of people thinking and or on Ozempic to not do it.
I can just hit a search engine and say "number of calories in X" and get a precise answer with 2 seconds of calculator math.
If I have to take a picture, send it to ai, but then amend it with "This is air fried chicken, it weighs x, it's a breast cut. I didn't add salt."
Why do all that when a single search will give me the answer I want without the picture upload or context?
Overall I am a bit obsessed but not that obsessed to the point it needs to be exact on-point precise.. just give me an idea of where my calorie count stands for anytime of the day. Just be way better if it was done auto-magically and Im betting this will be a good future use that gets people excited for smart glasses one of many upcoming innovations with them.
A pan-fried chicken with a little oil in the pan to avoid sticking/make better thermal contact will add calories but not 3-4x more. You're likely using about 1 tbsp of oil which is around 100 kcal. 100g of chicken has around 160 kcal. Even assuming all the oil ends up on the chicken (it isn't) that's ~2x the calories at most.
Perspective wise, though, it'll by the white rice or mashed potatos that are more problematic in terms of calories. Both have a load of calories and can't be eyeballed by camera. It's all about the weight for those. And if you threw in butter/oil, even harder to know what the actual calories are.
Having smart glasses automagically telling u how much your consuming for each meal & total caloric daily intake via audio or visually within the glasses i think would be powerful! Majority of people have no idea how much they consume and I'm betting they consume anywhere between 2000 to 6000 (heavier people) calories.
As for and noted I eat out always a health-ish chains. The AI is getting the info directly from their sites, so taking a pic the AI knowing my location/what restaurant and matching it with pics restaurants post ..it will be seamless vs. having to now pull out my phone and tell GPT or take a pic.
For the sell process, like with any open-source project whether it's an NPM package or anything else, there are no absolute guarantees... that's just the nature of open ecosystems...
But I've built Workout.cool with transparency in mind, no hidden business model, and self-hostable.
Just what I can tell you is this :
I've been passionate about fitness my whole life let's say. I started sports at 3 years old, and I've been into strength training for over 15 years.
I didn't build this to make money. I built it because I genuinely care and because I see more and more people missing out on the benefits of training, often overwhelmed by complexity, closed ecosystems, or paywalled apps, including people close to me, like my sister.
Hope that my reply counts for something...
One note: if you're using the same video set as workout.lol, the one that loaded for me (male_dumbbell_hammer_curl_front_ani.mp4) could be compressed from 3.3mb to <300kb with little quality loss.
I’m only embedding YouTube videos now, all with permission or public use from the original author.
If you’re into 3D or want to help create open assets, I’d love to chat!
I sold the app to a guy who seemed to just abandoned it. I also texted him multiple times if he needs support, but he didn't answer anymore. It makes me really happy to see it being maintained again!
Great work on the UI improvements.
You have no idea how happy I was when I saw your name pop up ahahha
Yeah, no luck either. It really broke my heart to see the project stall like that.
That's what pushed me to rebuild everything, keeping the same open spirit you had from day one.
Thanks a lot for the kind words about the UI it means a lot coming from you.
And if you ever feel like jumping back in (I totally get that it might be tricky, especially since you sold the original project and this one is so close) but you’d always be welcome.
Your input, ideas, or even just your presence would mean a lot !
Cheers !
Dunno how useful it would actually be, but an interesting thought.
Sorry for that
It appears to be hosted on Vercel...
If he really wanted to stop the project, he should've put the repository on private and put down the website, but he just left everything the same as it was.
I’ve been working on an automated calendar scheduling api that integrates with Apple CalDAV (iCal) that lets you schedule your life around goals (it uses Google OrTools to solve a great big CP-SAT constraint model blazing fast, a year in under 5 seconds), along with meal planning around macro goals. I knew I wanted to integrate a workout/training plan system but had no idea what component I’d end up using.
Now I know! Thanks for building this project.
I'd love to hear more about your setup and if Workout.cool can fit as a "component" let's say? in your system, that's exactly the kind of use case I built it for. Open, hackable, and easy to plug into more powerful workflows. GG !
One feature request I'd add to the pipeline is to filter exercises available by Gym. Planet Fitness is ironically super unfriendly to beginners and limited in what they offer. People could add the exercises available at their gym and grow the database. Conversely, this could help beginner home gymmers plan what machines / weights to buy to maximize their routine.
Bcs It's true that most beginners tend to think in terms of "full body" or "upper body" rather than doing a structured split let's say. They don’t usually say "I want to train my posterior deltoids and lats" lol
I love the idea of filtering exercises by gym type or gym but can be hard to handle for "private" gyms and will also need some kind of moderation... Could work for large branded gyms though.