Succinates

To the supplement Gurus:

I was reading a rather dated article by a Champion Nutrition pusher, and it reminded me of when they released a supplement called 'Muscle Nitro' around '87.  I had just opened World Gym San Jose, and was enjoying having unlimited access to whatever supps I wanted to carry.
When I first tried Nitro, I really thought I felt an extra kick in my workouts.  It seemed to enable me to get a few more reps at the end of all my sets, where usually I would fail. Considering that at that time I averaged 1300mg of sauce/wk, do you feel it was just a placebo effect, or was there ever any credible research to support the use of mineral succinates as a training aid?
I also remember that after Champion changed the product from a very strong smelling tablet to a capsule, the kick seemed to vanish.

thanks,