Phrases about respiratory capacity sound clinical, but on a supplement page they sit inside general wellness language.
Capacity is a term normally tied to measured lung function. A supplement page cannot promise a measured change, and BreathiZen states it is not intended to diagnose, treat, cure or prevent any respiratory disease. The wording is best read as an everyday, how-you-feel framing.
If you are worried about your actual breathing capacity, a clinician can measure it. Supplement copy cannot. Use the page to understand the product, and use a professional to understand your lungs.