Hi Rosi, to answer some of your questions:
My current job is in an office working for about 7-8 hours a day, although it does not require much concentration. I cycle into work every day which is roughly 30 minutes.
Today (on my 3rd day of fasting) I decided to stop. There is no doubt I could of kept going for a lot longer, because after about 30 hours I really didn't feel the need to eat at all, plus the hunger pains start to dissapear (or you notice them less). The reason I decided to stop was I was struggling to get up in the morning and I didn't feel like cycling to work.
After 2 1/2 - 3 days I haven't noticed any 'detox effects' at all. Maybe this wasn't long enough, I'd been keen to try it again over a period where I don't have much on and take it a step further. I lost about 1-2 kilos on the 2nd day, but no other weight changes on the 1st day or today.
A big realisation for me during the fast was how psychological eating is, rather then the physical need for it. I kind of felt like I was addicted to food (or sugar?) and was getting cravings on the 1st and 2nd days. I have seen huge benefits in my thought process towards food. I am so much more aware of what I am eating and saying no to food all together seems to have given me discipline to say no to those nasty foods which are so easy to pick at. My appetite has been reduced, probably due to the shrinking of my stomach and today I was content with just a tiny tub of rice salad and a tiny bowl of noodles for lunch and dinner.
Anyway, I'm definately glad I experimented with it mainly because of the insights into my eating psychology. I hope this helps
P.S If you talk to other people about your fast, expect to be hard pressed by their opinions on why you shouldn't fast :P