
Show HN: Video conference and synchronized YouTube video to do fitness in groups - dulyanov
https://www.co-train.space/
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dulyanov
Hey HN,

We've built www.co-train.space to stay fit while staying home. You pick
fitness video on Youtube, it plays synchronously for everybody in the group
and you see your peers thanks to Jitsi Meet (Zoom-like software).

I am now exercising with my parents every morning and feel much more connected
to them. Looking forward to hearing what you think!

~~~
m_a_g
First of all, it looks great, good job! My question is that why do you limit
yourself with only fitness? For example, study sessions are a great example
that can benefit from your product.

~~~
dulyanov
Basically it was the use case for me personally. I had to spend 2 weeks on
quarantine totally alone separated even from wife so we wanted to exercise
together. But yeah, I think you are right, there are many potential use cases!

~~~
amiga_500
My wife and kids do a drawing session with the grandparents, so this is
"instructor led from youtube":

[https://www.youtube.com/watch?v=8tjyfU0pHYc](https://www.youtube.com/watch?v=8tjyfU0pHYc)

As you say I'm sure there are many ideas.

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symplee
Feature idea: use the webcam to project the watcher's image/body onto the
instructor's. Then with some computer vision magic, gamify how close your
workout matched the instructor's workout.

~~~
gberger
That's not how workouts work, though. Each body is different, and people have
different skill levels too. It's not like Just Dance

~~~
frankdenbow
Using this type of method to check form makes a lot of sense. There were manny
Kinect apps that did this.

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thefreeman
Does this handle ad breaks? I think with a monetized video different people
may get different length ads at different places. Just curious how this would
handle that situation.

~~~
dulyanov
Oh, I think I did not test this. Completely forgot I have YouTube
subscription. I guess it should be possible to detect when and starts and
handle it. But sudden pauses due to ads can ruin UX especially for fitness...

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Zenst
What kind of issues did you have syncing with youtube videos and what kind of
latency do you experience?

BTW Great initiative and certainly could use that tech for many avenues like
remote classroom, any presentation with Q&A. Few others I suspect, but great
start.

~~~
dulyanov
Technically syncing is easy, websocket + Youtube API. The biggest issue for UX
though is that a user should click on the video at least once. Otherwise,
Firefox will block sync commands.

The latency can be 3-5 seconds for the first sync, when the video is
initialized and unbuffered. For the next syncs its < 1 second.

~~~
Zenst
Interesting as I would of thought fitness video's would need tighter latency
due to the beat, but then, that can actually work in your favour as the beat
will be way less than a second, so could always sync upon that for what would
appear to be perfect sync, yet 1-3 beats offset beat out of sync and yet the
illusion of perfect sync.

With workout videos usually 120-140 BPM, sub second, let's say 1 second for
ease on 120 BPM would be 2 beats per second and so a sync of 2 beat offset
would be spot on. Now a 140 BPM would be 3 beats, but you get the idea. By
syncing the beats with an offset to cater for the latency and the BPM, you can
give the illusion of perfect video sync. More so when doing repetitive motion
to that beat, just seems like it would work really well. Certainly makes
management of latency a much more easier task and allow for buffering as well
depending upon how many beats you want to offset, so could handle latency
spikes and brief drops. Which again, makes the things easier when you can
control and fix latency , though as you can't do that, planning it out of the
equation is always a treat. Food for thought perhaps.

But it is your baby, you pick the formula you want to feed it. But hope you do
well whatever direction as certainly has potential in many avenues. Remote
rave anybody :).

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ghostbrainalpha
I bought a projector just to make my fitness videos life size on the wall. It
sounds lame but it has helped my mental health.

Adding the video conference element is a really great idea. Now I just have to
find the best place to mount a webcam.

~~~
symplee
Not crazy at all. This is where the industry is going anyway.

For example "Tonal" is a work out machine that attaches to the wall, with a
large video screen (probably larger in the next generation version).

[https://www.youtube.com/watch?v=LdV2U6NxVUY](https://www.youtube.com/watch?v=LdV2U6NxVUY)

Regarding your wall projector, it would be cool to have a camera project your
image onto the instructors. Then some computer vision magic to grade how close
you matched their exercise.

~~~
_curious_
"This is where the industry is going anyway."

Just because a company offers a product that does something new and different
does not equate to where the industry is truly going (as much as founders/CEOs
may wish otherwise).

It's more about where the customer/consumers are going...yes you can lead them
to an extent, but on that note are products like Tonal actually selling and if
so, what clip and density?

I would ask for evidence of adoption of something (beyond just the mere fact
it exists) to support the "where the market is going" type of thinking...

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jops
Nice. Most of the instructors on our system* have pivoted to run their classes
online like that now too. YouTube or Vimeo synchronized with a live Zoom.

It's actually working really well for them as they can now open to a wider
audience! It's great to see how people have adapted so quickly in the
lockdown.

* [https://bookwhen.com/virtual-class-booking-system](https://bookwhen.com/virtual-class-booking-system)

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werber
It’s always so exciting when you have an idea, and then get out of having to
make it cause it was posted here first, love that about hn. Great job!

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_curious_
Really neat idea - I'm a fan anything that helps people improve their health
habits whether individually or collectively!

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dusing
Great work, this is exactly what my wife has been doing via Zoom and Youtube
with her gym class.

They had been watching the live feed each morning alone and found a lack of
motivation since they were used to working out together.

So there is a market for sure

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Tepix
This is pretty fantastic, not just for working out. Kudos!

~~~
dulyanov
Glad you liked it!

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shervinshaikh
This is great! I would love to see a version where you can Sync Spotify
playlists & have the fitness instructor teach live

~~~
ekulianova
Interesting idea! We'll certainly think about it

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vutekst
I want this but just for watching general youtube videos sync'd with people

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jvm_
There have been these posted here, I forget their names though.

I've been thinking of doing some with all my Aunts watching their 60's-80's
home videos. They all Zoom in, watch it synchronized and commentate. Would be
interesting to have the family history documented, otherwise it's just an old
video of a familiar face in some place.

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drewbeck
This is great. The UX is awesome. Do you have limits on number of users here?

~~~
shervinshaikh
Yes I'm curious on the number of users too!

~~~
dulyanov
Youtube sync should work for lots of people.

We tested video calls in a group of 8, it was working well. I heard that
having around 35 people in one room can make it unstable.

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ekulianova
Great idea! Tried it with mum, worked quite well!

~~~
BubRoss
It's a little suspect that you and multiple other names made accounts just to
post simplistic glowing comments about how excited you are to work out with
your mom, just like the person who posted this.

~~~
ekulianova
Hey! I personally followed HN but never commented before so had to login only
now when news about our platform was posted. Didn't see multiple simplistic
comments except for dpie123's who is my friend and an active user of co-
train.space:)

~~~
akiselev
_> I personally followed HN but never commented before so had to login only
now when news about our platform was posted._

Register. Not login. Your account was created about two hours after this post.

 _> Didn't see multiple simplistic comments except for dpie123's who is my
friend and an active user of co-train.space:)_

Their account was also created around the same time - after the post.

~~~
ekulianova
I don't argue with that, I mixed up the terms "registered" and "logged in"

Can't understand negative reaction about 2 new registered users

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frequentnapper
does this allow anybody in the group to pause/move anywhere in synchrony

~~~
dulyanov
No, there is only one Host who governs the video, everyone else has no ability
to change the timestamp or stop the video.

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dpie123
Cool app! East to use and fun! Best for corona time!

