The damage from cortisol is highly overrated. First off, cortisol is not constantly secreted throughout the day. Second, your levels would have to be constantly elevated similar to the way it's seen in people with AIDS in order for muscle wasting to occur. All you need to know about cortisol in regards to training is the specific times during the day such as in the morning or post workout when those levels are elevated above normal. This can easily be managed with 1000 mgs Vitamin C upon waking up and post workout.
Extreme muscle loss post cycle is misinterperted by many people. Most of the time, it's related to water loss and the user then reports that he lost muscle in an exaggerated manner.
Proper PCT, an adjustment to your nutrition and consistent training are the factors invloved in long term progress.
Jenetic