The latest Gym Bro pseudo-science has 2 schools of thought: One, is to do no cardiovascular (aerobic) training at all, it is unnecessary for fitness and fat loss; second, is to only use high-intensity interval training (HIIT) for cardiovascular fitness. Both of these schools fail. Cardiovascular endurance is one of the main components of fitness, as discussed here last week. However, cardio training should be performed correctly for maximum benefit. Read this article for tips to improve your aerobic training.