Skeletal muscle adapts to a progressive overload, but the response can vary between different modes and intensities of exercise. Generally, a minimal threshold intensity of 65% of the one repetition maximum (1-RM) is needed to elicit muscle hypertrophy; however, recent studies have challenged this hypothesis and have provided evidence that low-intensity training (LIT) combined with vascular restriction (KAATSU) may also elicit increases in muscle size and strength. The physiological aspects of applying vascular restriction during exercise are not fully understood and may be explained by several factors. Examining the results of previous studies may help elucidate the factors responsible for the adaptations associated with vascular restriction in humans. Therefore, the objectives of this review are to summarize current knowledge regarding the physiological adaptations of skeletal muscle after low-intensity exercise combined with vascular restriction, the different training protocols used to elicit adaptations, and suggested areas for future research.