I did not, but I did start in phase 2. I started at about 5-6 weeks on SBD with treadmill walking. If you were already exercising, you should be able to continue. Phase 1 usually gives me a headache for a few days and fatigue for a week or so, so I didn't even attempt, if you feel well and want to, there is no reason you can't.
"Blessed is the person who has earned the love of an old dog." Sidney Jeanne Seward