I'm often asked this question and here is my response...
You may want to have a small protein shake of 1 scoop protein powder, some water, and maybe a little full fat coconut milk. (No low fat coconut milk...what's the point.)
Maybe a small handful of almonds and a half an apple.
For others, it may just be some coffee or my favorite, mate´.
You'll need to experiment to see what works best for you.
For after your boot camp session there are conflicting theories on when and what to eat.
Some say that you should just eat protein and fat...or many say this is a good time to add more carbs such as fruit plus the protein and fat.
I prefer that you have a wholesome breakfast with protein, vegetables, fruit, and some healthy fat.
Skip the complicated formulas...just eat as close to nature as possible and your body will take care of itself.