Hello! I have done functional training with high intensity my entire life (which is like15 years now). Nowadays, I train 4 to 6 days in a row, and then I take a rest day.
My basic training day starts with running or rowing 30-45 min with high intensity (interval training) in the mornings. In the evenings, I do some kind of strength training (different squats, cleans, snatches, deadlifts, all major lifts), with sets of 5x3, 5x5, or 5x10.
After the strength training, I usually do two different metcon workouts with 5-10 minute rest in between. For these, I use broad time domains from 1 minute to 30 minutes. I also try to use big weights and my body mass in the metcons. I always hammer the metcons with full intensity.
I believe that my ability to train so much and with so hard intensity is because I have created a careful foundation of physical capacity starting at very young age. When I started doing CrossFit, I followed the main site workouts strictly. But nowadays I want more volume than the main site provides. So I do a bit more for training days.
There has been some kind of talk about me gaining muscle mass after the European Qualifers, but that is not true. I have had same body mass now for a few years (80kg). Also, I don't have access all the equipment that is needed for all the main site workouts, so occasionally I have to modify some of the movements.