I just visited their website and ‘chatted’ with a person. Here is the result:
“Q: Do I have to take the Suspension and Functional Training Courses before I can do the Group Training?
A: It is not required, but recommended.”
While it certainly won’t hurt, you would not have needed to do that.
I think it would depend on how familiar you already are with group exercise principles, how to use the TRX, and TRX terminology. TRX has a specific way of naming and cuing their exercises, and an order of doing their cuing. So, if you want to work at a place that does very formal TRX classes using TRX lingo, then you might want the basic suspension course first.
Just one trainer’s opinion, but I got a lot out of the STC. Since there was no GTC at the time that I took my first TRX certification, I used the skills I learned in the STC to design my TRX group-ex class. Although I’ve never taken the STC, I didn’t need it because I know how to put together a group-ex class. Since then, I’ve been to their training center twice and taken several of the 2-hour sessions at fitness conventions – more than enough reminder education to keep my classes fresh and interesting (I don’t even teach with TRX equipment any more, I use CrossCore, but their training applies to the equipment that I use).
It is interesting that people have not done more with suspension style equipment before TRX. It isn’t like it there was no suspension equipment available before this. I was using gymnastics rings set low over a mat to work strength 40 years ago. TRX has done an awesome job of bring a user friendly system to our industry. I own two myself. I would recommend that if you do not have any idea how to use them, that you do take the intro courses. And if you are using them, but are not completely comfortable and familiar with the physics involved, use them more and with that purpose in mind. If you have doubts on running a class, take the group class training. I have not taken the classes, but would be interested in knowing if they teach spotting techniques and progressions/regressions, etc. Those are the most important parts of using any piece of equipment with clients.