Vladimir Issurin, one of the pioneers fronting BP [Block Periodization] training, states that BP has taken different forms according to the positions and experiences of those who presented them. He himself defines BP training as 2–4 week mesocycles with highly concentrated workloads directed at targeted training abilities, carried out in a specific order ("accumulation", focusing on basic abilities; "transmutation", focusing on sport-specific abilities; "realization"; focusing on recovery and peaking toward competition). Each of these blocks will then build off the physiological adaptations of the prior training block. On the other hand, others define shorter training blocks (~1 week, ie, microcycles) as BP training and have generally a slightly different approach to the concept. The main difference between Issurin’s and the alternative BP model is that, roughly speaking, Issurin focuses on concurrently developing a small selection of abilities in each mesocycle. In contrast to Issurin’s model has the alternative model a more unidirectional focus on one specific ability in each microcycle, which has similarities to the model introduced by Professor Verkhoshansky in the 1970s. In this paper, we define BP training as either one or more blocks with ≥1 week duration of concentrated training focus with either a uni- or multitargeted approach, which means that both BP models are included.