He often exercises / He is often in the habit of exercising.
这个短语的来源是由动词"锻炼"（exercise）和副词"经常"（often）组合而成。
例句：
He often exercises in the morning before work. (他经常在上班前早上锻炼)
She is often in the habit of exercising at the gym. (她经常在健身房锻炼)
I want to make exercising a regular part of my routine because I know it's good for my health. (我想把锻炼变成我的常规活动，因为我知道这对我的健康有好处。)