IHHT explained: what research says about hypoxia-hyperoxia training
Alternating low-oxygen and oxygen-rich air, at rest or during exercise. What studies show about endurance, cognition and recovery between intervals.
IHHT stands for intermittent hypoxic-hyperoxic training. Through a mask you breathe alternating low-oxygen and oxygen-rich air, guided by your oxygen saturation. No pressure and no chamber are needed. You will find every study in this article in our research library.
The principle: stimulus and recovery
A short period with less oxygen is a stimulus the body adapts to, much like training at altitude. In classic hypoxic training, normal air follows. In IHHT, oxygen-rich air follows. The idea: recovery between stimuli is faster, so the same session feels less demanding.
What the research shows
A systematic review brought together the controlled studies on repeated IHHT at rest (Behrendt et al., 2022). The studies reported improvements in exercise tolerance, peak oxygen uptake and cognitive performance. The authors call IHHT a promising non-pharmacological approach and ask for larger studies.
In healthy young men, the same research group compared cycling with oxygen-rich and with normal-air recovery intervals (Behrendt et al., 2024). With oxygen-rich intervals, oxygen saturation recovered faster and heart rate and lactate stayed lower.
In a study with healthy older adults and people with early memory complaints, participants completed fifteen IHHT sessions in three weeks (Serebrovska et al., 2022). After training, the brain responded faster to cognitive stimuli, and signalling proteins rose that the researchers see as possible drivers of cellular adaptation.
A common question is whether alternating low and high oxygen adds oxidative stress. In a crossover study with 21 healthy men it did not: oxidative stress and antioxidant capacity stayed the same (Susta et al., 2020).
Who IHHT suits
IHHT is compact, works without a chamber and combines well with training, coaching and recovery programmes. That makes it interesting for sports clubs, practices, vitality programmes and home use. Unsure whether to choose IHHT or a chamber? Read HBOT or IHHT.
The studies mentioned were carried out by independent researchers and published in scientific journals. Protocols differ per study. We present the results in abridged form and for information only; the original publication prevails. All sources are listed in our research library.
View the IHHT systems or try a session in our showroom in Goes.
