what sort of calorie intake are you doing?
I can tell you, I will be having a hell of a time shedding the excess fat off my body. I believe that it will come during the class: jitsu work, boxing, kickboxing, and the cardio portion at the end of the night.
Are you athletically in shape is a good question to ask of yourself.
In the 1st few weeks you will be sore as .... and will have a hard time getting sleep if you do any form of ground work.
I could not find a comfortable place to lay my neck after having been submitted with 11 guillotine chokes on my 1st night. My entire body was torn to shreds with the conditioning that they pushed me through. By the time I got to the cardio portion 2.5 hours in I had no water or food that had entered my system for 2-3 hours prior.
I was pretty light headed after loosing several ounces of blood and being semi dehydrated.
The instructor's wife who runs the cardio segment saved me that night. I got through half of the cardio before gassing out from pure exhaustion and had a quarter of a half liter bottle of water. Went straight back and forged on. the water was necessary but I cramped up horridly during some jump-work in my core.
I will advise you to find a very comfortable way to fall asleep for the 1st few days/week that you start.
hope this helps.
Throughout life there are bumps along the way some may be painful...others not...who gives a damn in the end you'll still die