The BOLT Test: How Efficient Is Your Breathing?
The BOLT test (Body Oxygen Level Test) measures in seconds how your body responds to CO₂ ‐ the best simple indicator of your breathing efficiency. All you need is a timer: it is built in below.
- Sit upright and take a few calm breaths through your nose.
- Take a normal breath in and out through your nose.
- After exhaling, pinch your nose and start the timer.
- Stop at the FIRST clear urge to breathe ‐ not your maximum. Swallowing, diaphragm tension or the desire to breathe count as the signal.
0
What does your score mean?
Enter your details and you will instantly see your full breakdown: what your score says about stress, sleep and performance ‐ and which training improves it.
Your full breakdown
| BOLT score | What it means | Recommendation |
|---|---|---|
| under 10 | Strongly reduced breathing efficiency ‐ your breathing centre reacts very early to CO₂ | Daily light nasal breathing training, no intense breath work yet |
| 10-19 | Reduced ‐ typical with stress, mouth breathing or poor sleep | Functional breathing training focused on light, slow breathing |
| 20-29 | Moderate ‐ solid base, room to improve under load | CO₂ tolerance training and breathing patterns under exertion |
| 30-39 | Good ‐ efficient breathing at rest | Performance-oriented training: breath holds in movement |
| 40+ | Excellent ‐ high CO₂ tolerance | Maintain and apply sport-specifically |
Important: The BOLT score measures your own progress ‐ test in the morning right after waking for the most reliable value, and compare yourself with yourself, not with others.