I have had mixed results.
Last year I lost 22 pounds in 4 weeks with ip and exercising intensely 5-7 days a week.
In January I returned to phase 1 for 13 more pounds. I still work out pretty much every day.
My losses have been very slow this time.
Read the older exercise thread.
My advice is unless you are already a obsessive exerciser (which I admit I am) I would not start anything too strenuous while on phase 1.
If you can find something you enjoy, Pilates, yoga, even Zumba, start slowly and see how your body reacts.
Maintaining since April 2011.