My first Master Cleanse from May 11-July 9, 2009, was sixty (60) days. I felt great during it, and really, I could have kept on going. The most difficult part was the cravings, mostly psychological, but the cravings got progressively easier to deal with after Day 35. It frankly took me one month before I settled into the cleanse and before I really noticed my body shift into cleansing mode.
I used to be a runner but I've suffered some neurological injuries that make sustainable running elusive. On that 60 day Master Cleanse, however, I ran more than I had run in over eight ( years. From Day 10-Day 21, I ran 12 days straight -- having probably run only 12 days in total over the previous three years -- and worked up to over 10 miles. As I developed some concerns about my adrenals, I stopped running after Day 21 (and did no substitute exercise), only to resume running on Day 49, working once again up to an over a 10-mile distance. My times continued to improve and my heart rate continued to drop.
Interestingly, I noticed that my abililty to sustain running due to my neurological issues waned quite rapidly after I broke my Master Cleanse. In other words, the neurological symptoms reappeared. Within 3 weeks, I was having difficulty running 3 miles.
There is something magical about the Master Cleanse and its ability to restore my neurology, even if temporarily. It inspired me. For that 60 day window I felt like my old self again.
I'm presently on Day 16 of my fourth Master Cleanse, and once again I am running. On Day 14, I ran over 7 miles. Just last month, on vacation in Mexico, I had difficulty running 3 miles around a track across the street from my hotel, and in a two-week period, only managed to run 4 times. In the first 14 days of this cleanse, I've run 7 times. These results aren't a fluke. I just want to keep them and make its restorative powers permanent.
I cannot speak for everybody; I can only report my own experience. I never had a shred of weakness or a moment of uncertainty in health, strength, or vitality while doing the 60 day Master Cleanse. It was the gentlest, most effective cleanse I've ever done. I would have no reservations about doing or encouraging anyone to undertake a prolonged Master Cleanse, with the caveat that one must listen to her body and her needs. While a 60 day cleanse is not necessarily warranted for many, based on my personal experience, I would have no hesitation in endorsing it.