What do you mean by "anaerobic workouts?" Interval workouts that take you near your anaerobic threshhold on the blasts? If so, then they should be done no more than 2x/week. Once a week if you are just beginning them. Some people (athletes) may be able to do them 3x a week with no negative effects.
Or do you mean weight training, which is an anaerobic activity? If so, then any number of systems would work: from a full-body workout 2-3 times a week (2 is minimum) to a split routine that has you work each body part just once a week, heavy and intense---something you would ideally work up to by doing first a 2-day, then a 3-day, etc. splits).