We all had tons if questions when we first stumbled upon this site. Many people here are super helpful, so never feel bad for asking questions.
I had the same concerns about CG, especially since I do martial arts 4-5 days a week. The first thing to keep in mind is that co-washing (using only conditioner to cleanse your hair) is not mandatory for CG. The definition of CG is eliminating sulfates and silicones- how you do that is a personal preference. The second edition of Curly Girl by Lorraine Massey (where the name CG came from) does indicate that sulfate-free cleansers can be used. There are an abundance of sulfate-free shampoos (low-poos) to choose from- just make sure you choose one without silicones. I still rotate in a sulfate shampoo once every few weeks, usually when I do my PT/DT, but I found one that's silicone-free and extremely gentle. I found that the biggest improvement in my hair was from eliminating non-water-soluble silicone from my hair products, especially my cleanser and conditioner, because I was able to get more moisture into my hair.
I found that I can co-wash as long as I use a very light conditioner (my favorite is VO5 Vanilla Mint Tea) and massage my scalp really well while cleansing an while rinsing. There are also "cleansing conditioners" available, that will give a little more cleansing power than regular conditioner, but will still be gentle on hair. I'm a huge fan of these.
3a/f/iii Before the chop- Donated to Locks of Love, January 2013
Modified CG since 11/5/11
CO-WASH: VO5 Vanilla Mint Tea Clarifying, DevaCare No-Poo
CLARIFY: CHS Treatment Shampoo (used prior to PT/DT)
RO: DevaCare One Condition, Regis Olive Oil
LI: Cure Care, As I Am Leave-In
STYLE: Re:Coil, Curl Keeper, Biotera Gel, Deva Ultra Defining Gel, GVP Liquid Sculpting Gel, Curls Rock Amplifier and Strong Hold Mousse
PT/DT: IAGirl's PT, One n' Only Argan Hydrating Mask