It seems like a few others have had or are having similar experiences. I don't know what it could be other than possibly A) something from the diet being recirculated or B) excess stored up toxins being "dealt with" and released, both of which could result in greater levels of fatigue due to the body using more energy to address those issues. I know this kind of thing is not unheard of -- maybe even common -- when starting up UT, or many other cleansing procedures. Just how long this "die off" phase usually lasts, I don't know, and it probably is highly variable depending on diet, current state of health, exposure to clean air, sunlight, etc. ... and probably a billion other factors!
Whether it's because of some "die off" phase or "healign crises" or something like that, who knows, but I do know it's not uncommon...
However, in MY experience, I haven't noticed any increased tiredness at all. Infact, quite the opposite. I've been doing UT for a few weeks now, primarily the morning urine (about a cup full), and sometimes some more throughout the day if it's convenient to do so. Since I've been doing this, I've actually noticed myself sleeping LESS and feeling less prone to "nod off" during the day ... and just a general feeling of being more "alert" and "awake". I don't know if this is from UT or not, it could be from other areas that I've been working on too -- or a mix of different factors -- but one thing's for sure, it definately hasn't made me MORE tired or fatigued or feeling "bad" or anything like that. So, I just thought I would share that!