For ACE certified trainers, which additional certification will boost your income: the GFI or LWMC certification? For me the purpose of a certification is to prove that I am qualified; individual CEC courses are helpful to me and my clients but won’t do anything for my resume. I can only afford one additional certification this year and I want it to be an investment that pays off financially.
I agree with Marianne but this will apply only when you are actually planning to teach group exercise. This would mean that you become a part-time employee or subcontractor at a club. Be aware that picking up clients that way can potentially put you in conflict with the club if you do not plan to train them under the Personal Training program that this club may have.
You mention that the additional certification is only to demonstrate that you are qualified. That would tip the scales towards the LWMC certification. I hold this certification myself, and it is for the same reason.