I find it relatively easy to reach sleep paralysis, usually getting the full heavy feeling in about 5-10 minutes.

The problem is that I can stay completely still for almost 30 minutes after reaching SP, I get a very small amount of HI, and I just get bored (frustrated), and get up and do something else, like go on the computer.

Could this be a sign of not having enough physical activity during the day? What other reasons would this happen?

It seems to be one of my only boundaries keeping me from getting another LD.