Heaviness when trying WILD

Last night I woke up at 5 AM. I decided to try to fall asleep consciously. Because I feel to be awaken too much I was relaxing in bed and listening to music. After some hypnagogic hallucinations (wanted to try HIT) I suddenly felt my body is very heavy. The heaviness was similar to heaviness when restarting lucid dream after premature awakening. I turned off the discman and started gently focusing on the heaviness and thinking about nothing. After a while I felt SP and entered to a dream.

So, my question is: Is the heaviness true deep relaxation necessary for WILD?

I find that I tend to feel heavy when I relax deeply, and trying to induce a feeling of heaviness is often used in hypnosis or relaxation, I think.

Thanks, now I know how to do WILD better.