Our goal is to be able to chant the Name of God continuously and with concentration. Keeping this in mind, we can make efforts to chant at all times in any position – whether we sitting cross-legged, standing or walking.
For example, we can chant while lying down, watching television, cooking or going to work on a train.
While sitting to repeat the Name of God, we should be comfortable or else we could be distracted by any discomforts, preventing us from reaping the benefits of chanting with concentration.
It would be pertinent to add that we can derive maximum benefit by sitting in a cross-legged posture. The reason for this is the spiritual energy generated by chanting the Name of God circulates within the body due to this posture. An open posture such as lying down on the bed, etc. can dissipate the energy into the surroundings.
As an experiment, try repeating the Name of God while sitting in a casual posture and while sitting in a cross-legged posture and see if you can perceive the difference.