I agree that it is not normal or natural to make children sit through the meetings without a break, but it is not healthy for adults to do it either.
If you were employed somewhere and had to sit for two hours without going to the toilet or get a cup of tea the company would be in trouble. I know some people probably say that they do do this which is fine if they choose to but a company cannot make someone do it. When I worked at a computer we were encouraged to take breaks from the screen every 15 or 20 minutes for health reasons.
Furthermore, I always got up and went to the toilet in the song to stretch my legs and free off the pain from sitting as I have had many problems and operations on my hips. I also had to eat a banana in the toilet so as not feel nauseous for the rest of the meeting as I am on strong painkillers which effect my stomach.
In the end, we used to go home after the first meeting which made life a lot easier and was the start of our fade.
I recently had to attend a Speed Awareness course which was due to last four hours. During this time we were given two breaks with cups of tea and biscuits etc.
Apparently the human brain concentrates best in 20 minute intervals so when studying for my exams I used to take a break every 20 minutes which did improve concentration and retentive memory.