atkins has a 2 week introduction phase where carbs are kept to 20g's a day and then after that , carbs are slowly introduced back into the diet. the atkins diet seems to be geared more for sedetary people. the ketogenic diet is geared more toward athletic people as it allows at least 30g carbs/day plus the 24-48 hour carbup for replenishment of glycogen stores in order to provide strength for workouts/muscle growth. In a nutshell.
"If you have the desire or ability to talk between sets then you aren't working out." - Mike Mentzer