Fasting before I start my weightlifting routine?

I'm going to start a weightlifting routine where I hope to gain 20 pounds in 6 months. I'm going to start tomorrow. I decided to fast just to get all the toxics out of my body before I start the program. It has been about 26 hours of only water and lemon juice. I was aiming for 48 hours, but I'm wondering if it counterproductive. How long do I need to fast to get all the crap out of my system?|||i wouldnt do that , by doing cardio eating clean foods and drinking plenty of water you can clean your system.