IHHT Altitude Training

A 45-minute intermittent hypoxic-hyperoxic training (IHHT) session using controlled altitude simulation to improve mitochondrial efficiency, oxygen utilisation, and cardiovascular resilience.

Intermittent Hypoxic-Hyperoxic Training (IHHT) is a passive altitude training method that alternates between breathing hypoxic air (reduced oxygen, simulating altitudes of 3,000-6,000m) and hyperoxic air (enriched oxygen) through a comfortable face mask. The client lies or sits in a relaxed position while the system automatically cycles between these two conditions, typically in intervals of 3-5 minutes of hypoxia followed by 1-3 minutes of hyperoxia, for a total session duration of 45 minutes. The physiological rationale is based on mitochondrial selection pressure. During hypoxic intervals, damaged or inefficient mitochondria (which have a lower threshold for oxygen deprivation) are triggered to undergo apoptosis — programmed cell death. During the hyperoxic recovery intervals, the body's mitochondrial biogenesis pathways are stimulated, producing new, healthy mitochondria to replace those that were eliminated. Over a course of 10-15 sessions, this process can measurably improve the overall quality and efficiency of the cellular mitochondrial population. The clinical effects of IHHT are well-documented in European sports medicine and longevity research: improved VO2 max without physical exertion, enhanced oxygen utilisation at the cellular level, improved cardiovascular resilience, better altitude acclimatisation, and reduced oxidative stress. For longevity specifically, the mitochondrial renewal effect is the primary value proposition — healthier mitochondria are associated with slower biological ageing, better metabolic function, and greater cellular resilience to stress. At Circle Health, IHHT is typically recommended as a course of 10-15 sessions over 4-6 weeks for initial mitochondrial conditioning, followed by maintenance sessions every 1-2 weeks. Heart rate and blood oxygen saturation are monitored throughout each session to ensure safety and optimal training intensity.