Master cleanse and running a 10k

I am doing a master cleanse/ juice fast with a partner. We master cleanse drink all day and juice at night. I am not asking for advise on this... but.... We are running a 10k race on day 10&11... we started a day apart... We ran 8k today on day 3&4...slow pace, around 6:16 average pace. Our usual pace is 5:30-5:40 ... It was a struggle to go any faster... has anyone ran 10k on or near day 10 of a juice fast? I am thinking of doing juice with plenty of greens (spinach and romaine) the last 2 days before the race and not doing any lemon and maple syrup... is it possible to run 10k on day 10&11 on juice only!