Play NYT Connections Puzzle #618 Tue, Jan 14

Find groups of four related words Need hints?

Solve NYT Connections puzzle #618 - Group 16 words into 4 categories: ACTIVE, FUNCTIONAL, RUNNING, WORKING, MEETING, PERIOD, SESSION, SITTING, BODY, FLASH, LENS, STRAP, CROWD, GULLY, PUFFING, SWANK.