especially during the first one to two hours post-exercise when recovery rates are greatest. Reducing carbohydrate intakes to 35 percent of consumed calories during P90X WorkOut  this period only serves to retard glycogen recovery, which normally can take 24 to 36 hours. Consequently, progressively lowering available glycogen stores will compromise energy and performance levels in successive workouts.

http://nationalfitnesspoint.com/p90x-workout/