Quote Originally Posted by faceonmars View Post
You have to discover what works for you. I personally would never wait 20 minutes ( or even 2 minutes ) . I try to immediately return to dreamland on WBTB attempts... but that is just me.
I find that WBTBs longer than 20 minutes wake me to the point that it takes an annoyingly long time to return to sleep.
If you're interrupting REM, that would explain why you feel worn off during the day. REM is a stage of sleep when your brain is recovering itself from the day stress and fatigue. Waking up earlier and shortening your REM just to recall your dreams at expense of getting full sleep is, in my opinion, unfavorable.
Again I'll say it is favourable to interrupt REM as it is at the end of the 90 minute sleep cycle after which natural brief awakenings occur anyway. Waking during N-REM leads to feelings of grogginess and fatigue as your brain has been brought from very low levels of activity into full wakefulness very suddenly. If I wake during Non-REM I typically say 'fuck this' and go straight back to sleep without thinking of LDing.
I set my WBTB alarm for 4am because for me I know I'm always in the middle of REM at that point, I wake ready to lucid dream and when I return to sleep I go straight back to dreaming in REM sleep with plenty of the cycle left to lucid dream in.