For more helpful zebra tutorials go to www.zebratutorials.com
If you open up Zebra and you check the envelopes you will see that there are a few knobs there that might no be familiar to you, for example the F/R knob and envelope type selector. With just these two you can create synced loops and even add a second sustain level. You can choose which stage of the envelope you want to loop, and you have great control over the speed of the loop. Furthermore, there is also a knob at the beginning of the envelope where you can set a delay level. The value that you set these knobs to is important and relates to envelope type/speed selector in the upper box.
With just this information you can have a lot of fun already, but if you really want to know everything about it I highly recommend reading the Zebra manual where this is all discussed in detail.
Have fun!
Jorgalad