I once increased my weight very fast (around 2-3kg/week), that time without doing workout, and using so called "supplement" by doctor. However, it left some stretch marks when my weight is decreased ...
I do 15 min of cardio on an elliptical trainer. Then, I do 20 minutes of circle workout involving 10 exercises with 30 sec of rest in between. I finish the cycle with 5 min of the elliptical. Same ...