My husband and I usually run 3x/week for 3-4 miles per time. In the winter if there is enough snow we will substitute the run with an hour of cross-country skiing. I'm a little concerned that I will not have the stamina to do these long workouts when I am in Phase 1, because most muscle energy comes from glucose. Does anyone have suggestions for keeping my energy up? Some people have said to have a serving of "good" carbs an hour before the workout, as I will use them up in the workout and it will not throw me off track. Others have said just not to do the hard workouts in Phase 1, but that's really not an option. Any words of advice would be appreciated.
Both hubby and I noticed that our energy was lower during our cardio exercises for phase I, but not so low that we couldn't do it. We didn't do anything special - no "good carbs" an hour before or anything like that - so maybe that would help some. My typical workout these days where I can't go outside (4+ feet of snow out there!) is to ride my Spin bike. I noticed that it was harder to get the resistance up to where I normally keep it, so I just dialed it down some.
Hubby did the same thing with his treadmill runs. He also didn't lift as much weight as he normally does at the gym.
By no means were either of us so weak or tired that we couldn't do the workouts.
Geekchick, good advice from Abadoozy. Don't give up the workouts... just do the best you can. It's only two weeks... Phase II will be here before you know it.
Cardio exercise in Phase 1?
Don't give up the workouts... just do the best you can. It's only two weeks... Phase II will be here before you know it. 
