Acupressure mats

[now here]

http://ecx.images-amazon.com/images/I/51z%2BLHIaVIL._SL500_AA300_.jpg

Are they any good?
I tried the Shakti mat ones and it was great (I felt both relaxed and energized).
Then I bought a mat with more nails and I've experiences uneven results... I often feel relaxed but also fatigued afterwards (like after to frequent orgasms). Sometimes I even feel a kind of dull back pain a couple of hours after a session. :eek:
Can to much oxytocin or endorphin release cause such side effects?
If yes; then why doesn't meditation cause such side effects?

Are acupressure mats with less nails better? How long should you lie on an acupressure mat?

[now here]

Hmm.. Perhaps this should have been posted in the "Health / Nutrition / Diet / Alternative Therapies / Healing"-section. Don't really know how it ended up here. :o Not that I wouldn't appreciate an answer from The Shen clinic. :)

[now here]

So now I've heard that it could possibly even have harmful long term effects! :eek: Should one take these suggestions seriously?

[ebenia]

I have used an acupuncture mat for a year now and I think it is wonderful. Sometimes my back or shoulders hurt a lot because of studying and being in front of computer, but then I just put the mat on my bed and go to bed having it under me and I relax instantly and my muscles feel so much better on the next morning. I usually wake up in the middle of night and I will just remove the mat and then continue sleeping. :)

Sometimes I just meditate on it and I love it.