锻炼

锻炼	duàn liàn	to toughen / to temper / to engage in physical exercise / to work out / (fig.) to develop one's skills / to train oneself
锻	duàn	to forge / to discipline / wrought
炼	liàn	to refine / to smelt
炼	liàn	variant of 链, chain / variant of 炼