Hmm most people are trying to explain a 2nd wind in the context of endurance sports.
From a combat sports perspective your “2nd wind” is the ability to recover from an adrenaline dump.
https://www.supremacybjj.com/how-to-help-with-the-adrenaline-dump/#:~:text=This%20is%20your%20body’s%20way,out%20after%20just%20one%20match.
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