Movement matters. Continuous sitting leads to many ailments.

Surely it matters. I have seen many people who have to sit on chair for whole day because of work and after long time they get many problem because of same. After visiting doctor they only get advice to not sit for so long. Keep moving.

So, it's evident that some simple stretching exercises while sitting in the chair of your work place will save medical expenses as well as your health.

True.. Only thing is that person should follow it consistently. 

Without consistency nothing can be achieved. This point was mentioned by me in the early threads of this discussion.

That is quite astounding research especially about heart rate and very significant, but I wonder what reasons would it have been for possible health hazards while watching television?

Same. All sedentary activities including watching TV without moving from the seat have the same ill effects.

It might be radiation coming out from television screen so does using mobile for longer hours could possibly impact harm to health. 

More than radiation, it's the inactivity that's disastrous. Moving in someway or other can arrest the harm caused by sedentary life.