A short supervised course of alternating low- and high-oxygen breathing, done seated with a mask. The findings that hold up are lower resting blood pressure, better walking capacity when added to rehabilitation, and less long-standing muscle and joint pain. Blood sugar, cholesterol, inflammation and thinking show weaker signals; claims about slowing ageing rest on cell and animal work. (Full Review)
| Marker | Target | Why |
|---|---|---|
| SpO₂ | ≥95% at rest; nadir not below 80% during hypoxic blocks | Establishes gas-exchange reserve and caps how deep sessions may go |
| Haemoglobin | 13.5–15.0 g/dL (men); 12.5–14.0 g/dL (women) | Detects blood thickening from repeated low-oxygen exposure |
| Haematocrit | 40–48% (men); 36–44% (women) | The viscosity-relevant number; the practical stop signal for a course |
| Ferritin | 50–150 ng/mL | Iron availability limits any red-cell or vascular adaptation |
| hs-CRP | <1.0 mg/L | Tracks the anti-inflammatory shift claimed for the protocol |
| HbA1c | 4.8–5.4% | The metabolic endpoint with the most direct trial support |
| Fasting glucose | 75–86 mg/dL | More responsive than HbA1c over a three-week course |
| LDL-C | <80 mg/dL | The lipid endpoint that moved in metabolic-syndrome trials |
| ApoB | <80 mg/dL | Counts atherogenic particles directly, unlike LDL-C |
| Seated blood pressure | <120/80 mmHg | The best-evidenced outcome of the intervention |
| RMSSD | No established population target; tracked as change from the individual's own 14-day pre-course baseline | Quantifies the autonomic shift the protocol produces |
| ALT | <25 U/L (men); <20 U/L (women) | Liver indices shifted in the metabolic-syndrome trials |
Cadence: Blood pressure, oxygen saturation and symptoms before and after every session; blood testing at 6 weeks, 3 months, then every 6–12 months if courses repeat, with the complete blood count brought forward if fatigue, headache or flushing appear