Reaction Time Trainer.

I am a beginner with Arduino and I would appreciate very much if you someone could evaluate item I need to project and help me to find best solution, please see following video link.
My original intention is to create something link this:

not wireless (I suppose to difficult) but cabled.
Did anyone already created similar project ??
Please, help me!
Thanks you.

There are a few ways to have fun. Buy a toy and play 24/7 or create something and enjoy the engineering.
What is it You want?

How many of those things are used in the video ? I think 8.
The “BlazePod” seems to use 6 of them and costs hundreds of dollars.

For the light, you can use a single LED or a RGB led for 5V, or a 12V led with a mosfet to turn it on.
To read the touch, perhaps a FSR will do (Force Sensitive Resistor 0.5" - SEN-09375 - SparkFun Electronics), but a switch (or a few) is probably better.

Can you make a mechaninal drawing ?
It could stand on three feet. There has to be a switch (or three switches) that can be pressed.

The sketch is not hard. Use random, show the led, read the input, even calculating the average reaction time is not hard.

What troubles me most is the exercise itself. That can’t be good. In my opinion such exercise is bad for your body. It is bad for knees, ankles, spine and what else. Can you show it to a physiotherapist ? I think the constant bending towards the ground with force is not good.

For touch, use touch sensors - the TTP223.

In case you wonder how it fits with what you show, you just create your own touch panel - such as a conductive gauze over the top of your light (it doesn't actually have to be touched, it will work over a small distance) connected to the bottom right pad on that module.

Not entirely sure whether that exercise is good or bad. What is bad for you is unaccustomed movements for which you have not trained. So some gentle build-up over weeks would be in order.

Should be quite straightforward to build a set of those things. The phone interface is the hardest part (and you will probably want something like that - to set the behaviour, and to keep track of performance).

Making them wireless isn't that hard. LiPo battery in each; operate the thing at 3.7V. Bluetooth connection from each, little MCU in there that reads the Bluetooth and switches an LED and reads some kind of touch sensor. +1 for the TTP223 based sensors (there are other boards as well - there exists at least one that's completely flat on the touch side, no pins protruding), they're great, very easy to use and very cheap to boot.

The most work is probably the phone app itself. User interfaces are a lot of work, hard to get right. But that price of US$399 for six of them does sound excessive to me.