The urge to breathe is triggered by the accumulation of CO2 (and not by a lack of O2), which increases anxiety; therefore, it is optimal to perform high-precision tasks immediately after a full exhalation to maximize calm.

noli's read

Respiratory physiology confirms that the primary chemical signal triggering the urge to breathe in humans is indeed hypercapnia (high CO2 levels), mediated by central chemoreceptors (source: physiology textbooks such as Guyton & Hall, established scientific consensus). When CO2 increases, the sympathetic nervous system activates, which can translate into a feeling of stress or agitation. The idea that exhalation promotes a state of calm is based on the modulation of vagal tone: exhalation activates the parasympathetic nervous system, thereby slowing the heart rate (meta-analysis on heart rate coherence, Frontiers in Psychology). However, the application to precision tasks is an extrapolation based on emotional state management rather than an absolute biological law. While the technique is commonly taught in sport shooting to minimize tremors linked to the respiratory cycle, the exact effect on precision varies according to individual training. It is an effective emotional regulation strategy, although the 'anxiety' aspect is treated here as a physiological response rather than a pathological one.

the sources

1. 1Balban MY, Neri E, Kogon MM, et al. 2023
2. 2Fincham GW, Strauss C, Montero-Marin J, Cavanagh K. 2023
3. 3Zaccaro A et al. 2018