锻炼
duàn liàn · HSK 4
to engage in physical exercise
💪🏋️ 锻 = forge metal; 炼 = refine by fire — forge + refine = train the body
锻 originally meant hammering hot metal on an anvil; 炼 meant smelting ore to purify it. Together they describe tempering steel, then by extension tempering a person through physical training.
炼 — fire radical 火 + 东 (phonetic)
Originally written 鍊 with the metal radical 金, meaning to refine or smelt metal by fire. The modern simplified form 炼 uses the fire radical 火 to show the heating process, with 东 as a phonetic component derived from 柬. The meaning extended from refining metal to training, tempering, or honing skills.