Discovery.com explains why people sit up and take notice when smelling salts (ammonia inhalants) are
placed beneath their nose. Ammonium carbonate is mixed with perfume to create a stimulant.
The ammonia fumes from the salts irritate the membranes of the nose and lungs,
which triggers a reflex causing the muscles that control breathing to work faster.
(this is how they relate to Weightlifting and Powerlifting HEAVY reps and sets!!)
They are used to revive athletes when they have passed out during sports or to revive individuals who have fainted
Ammonia inhalants/smelling salts defined: According to Columbia Encyclopedia via Bartleby.com:
Ammonium carbonate, (NH3)2CO3ĚH2O, is a colorless-to-white crystalline solid commonly known as smelling salts; in water solution it is sometimes called aromatic spirits of ammonia.