No pain, no gain, no idea what half these terms mean.
The practice of getting intoxicated or partying during intermissions at sporting events or other entertainment, essentially pre-gaming the second half. It's drinking between drinks, really.
The nervous system's process of activating muscle fibers to produce force—more technical way of saying 'making your muscles work harder.'
Using tools (foam rollers, massage guns) to apply pressure to muscle and connective tissue, because apparently muscles need their own massage therapist now.