This chapter introduces Intermittent Hypoxic Exposure (IHE), a “live low-train high” method involving short, repeated periods of breathing hypoxic air (9–15% oxygen) alternating with normal (sea-level) air while at rest. Typically, this follows a protocol of 5 min hypoxia alternated with 5 min normoxia for 60–90 min daily, 5–6 days a week, for 2–3 weeks. IHE utilizes much higher simulated altitudes (~2700–6000) than conventional training, inducing a significant but brief drop in blood oxygen saturation that stimulates oxygen processing adaptations. Historically pioneered in Russia in the 1930s for pilot acclimatization and later for health, IHE offers a flexible, low-stress, and convenient alternative to natural altitude. Studies show IHE can improve athletic performance (e.g., a 2.3% improvement in 3 km run time in controlled trials) and offers health benefits mirroring aerobic exercise, such as improved cardiovascular, respiratory, and immune function. The chapter also differentiates IHE (at rest) from Intermittent Hypoxic Training (IHT), which involves exercising under a hypoxic load, and related protocols like Intermittent Hypoxic Interval Training (IHIT) and Repeated Sprint Training in Hypoxia (RSH), which are showing promise in enhancing VO2max and anaerobic capacity.