Recent research strongly supports the way Pranaclimb interprets expressive and functional breathing — the grunts, breath holds, sharp exhales, screams, and sighs that naturally appear when climbing hard.

Baláš et al. (2023) observed that elite climbers generate elevated intraoral pressures during high-tension moves—evidence of brief, Valsalva-like breath holds that enhance postural stability and internal loading, even when no visible breathing cycle occurs. These moments, while absent from BR counts, represent significant ventilatory effort and metabolic cost.

Complementing this, Ikeda et al. (2009) found that forced exhalation alone significantly increased isometric muscle force, producing effects comparable to a full Valsalva manoeuvre but without the associated cardiovascular risks. This finding aligns with Pranaclimb’s emphasis on short, vocalized exhalations—such as grunts or sharp exhales—as efficient and safe ventilatory strategies under load.

Similarly, Srivastav et al. (2023) confirmed that controlled exhalation elevates intrathoracic pressure sufficiently to enhance trunk stiffness and support force transmission. These findings reinforce Pranaclimb’s rationale for incorporating such expressive breath acts into its BR correction model.

Further evidence comes from Chen et al. (2015), who demonstrated that yelling during maximal cycling efforts significantly increased oxygen uptake, respiratory frequency, and time to exhaustion. This suggests that vocalizations are not merely emotional expressions but reflect and amplify internal physiological load.

Lastly, the work of Vlemincx et al. (2016) highlights the regulatory role of spontaneous sighs, which act as parasympathetic resets and mark transitions into recovery. Pranaclimb reflects this nuance by assigning 0 or –1 BPM to sighs, treating them as signals of ventilatory downregulation. This is exemplified during the recovery phase of Margo Hayes’ Biographie ascent (5:23–5:28), when she emits three audible sighs—an observable cue of recovery and reduced sympathetic drive.

Together, these studies support Pranaclimb’s approach to adjusting BR for expressive and functional breathing patterns, ensuring that respiratory data accurately reflect internal load and energetic cost in real-world climbing scenarios.