Abstract Background Polarized training intensity distribution (POL) was recently suggested to be superior to other training intensity distribution (TID) regimens for endurance performance improvement., BLUF (Bottom Line Up Front) This scoping review compared the long-term effects of Polarized Training (POL) with other Training Intensity Distribution (TID) models—Pyramidal (PYR), Threshold (THR), and Block Training (BT)—on endurance performance and physiological adaptations. In endurance athletes ranging from trained to world-class (Tiers 2–5), POL and PYR models were generally more , Runners recruited were randomly assigned to 2 different training models based on HR intensity detected with maximal test. The percentage distribution splitted in zone 1, 2, and 3 were by 77/3/20 and 40/50/10 in polarized endurance training group (PET) and focused endurance training (FOC) group, respectively., Endurance coaches, athletes and scientists strive to find the best combination of intensity, duration and frequency of training sessions1 to achieve the desired physiological adaptation for athletes and the best performance during main competitions.2,3 Manipulating these variables dif-ferently over time is traditionally referred to as training , This review reports that the optimization of training in well trained cyclists cannot be solely explained by the training intensity distribution model and an individualized approach that considers the physiological and competitive requirements of the athlete is justified., ABSTRACT Background: Endurance sports demand a finely-tuned balance between training intensity and volume to optimize athletic performance. Training Intensity Distribution has become a critical training parameter in endurance sports, potentially eliciting superior physiological adaptations and improving overall performance outcomes. Training intensity distribution influences the body's aerobic .