Vital Signs 🫀 on Instagram: "Why You’re Breathless When You Work Out . . Getting out of breath during exercise is usually a normal response: muscles demand more oxygen, so breathing rate and depth rise. Breathlessness feels excessive when airways narrow (exercise‑induced bronchoconstriction), the larynx briefly constricts, fitness is deconditioned, or when iron‑deficiency/anaemia limits oxygen delivery. Cold, dry air, allergens, chlorine, or pollution can aggravate symptoms, as can pushing inte