I used to work swing shift; 7 of 3rdd, 2 off, 7 of 2nd, 2 off, 7 of 1st, 3 off. I personally had no issues. Then again, I am ex-navy so I am used to mid-watches, 70 hour days, not seeing the sun for days on end, and having to catch cat-naps.

No. If you have trouble switching hours for sleeping then it will remain difficult. If you have a job where you shift changes to different hours frequently you most likely will, over time, find it more and more difficult. A few things you can try is light therapy (to help reset your body clock). Stick to the same hours even on your days off. If you work graveyard M-F then Saturday and Sunday you live the same hours. Many people make the mistake of trying to live the weekends by daylight hours when they should just stick to vampire hours. Eat a proper diet and during the switch over eat more carbs during the first week of your 'day' (when ever those hours are) Carbs release sugars into the blood stream which will compensate for lack of sleep and will give your body the energy it needs. Stop eating high carbs when ever 'evening' (a few hours before bedtime for what ever hours you are working) And eat something with fats, proteins - Better yet something like turkey which also has added chemicals that make you nod. Fat and protein combined will make you sleepy which is needed the most when you are switching time. Jet lag is a serious problem and you will be going through jet lag each time you switch. So study up on jet lag - here is a good start: http://www.medicinenet.com/jet_lag/article.htm

It did for me, but then again, I'm an insomniac and can pretty much work anytime.