Some systems of meditation require us to meditate for one hour.
This is the time that it takes for our breath cycle to change over from one nostril to another and for us to naturally pass through the five chakras, and spend some time in AkAs’a tattva.
This could be why we are asked to remain silent, close our eyes and stay still for an hour.
I also observe :
For those who can’t sit quietly, pArAyaNam gives the same benefit..
If they also engage their minds in the meaning and feeling of the pArAyaNam, they can also have a taste of the higher chakras the sixth and the seventh.
Those who can’t handle solitude, may do group pArAyaNam, and get benefitted by the effects of others reaching higher chakrAs.