There is anecdotal evidence from the tactical fighter community which suggests that fighter pilots do experience a degree of adaptation arising from frequent exposure to high +Gz. The more they fly to high +Gz levels, the more they feel able to tolerate it. Is this increase in their tolerance due to adaptation of their cardiovascular system and/or baroreflexes to the high +Gz environment? Repetitive and frequent exposure to the high +Gz environment could act as a training or conditioning stimulus. If adaptation does occur in fighter pilots, it should be reflected in enhanced function, that is, the opposite of the situation that occurs with zero or microgravity exposure. This chapter examines the current literature dealing with cardiovascular adaptation in general and to high +Gz in particular.