How to say "sustained" in Japanese

• 持続的じぞくてきCommon
  na-adjectiveCovers the general sense of 'sustained' — something continuing without interruption over time. A versatile adjective for describing sustained growth, effort, or activity, and it also extends to 'sustainable' and 'durable'.
• 息の長いいきのながい
  i-adjectiveMatches 'sustained (effort)' and 'lasting (work)': it describes effort or a work carried on patiently over a long span, with an appreciative nuance of endurance. Less common than 持続的, so reach for it mainly in those lasting-effort contexts.
  息いきの長ながい仕事しごとになりそうだ。↗

  This is going to require a long steady effort.

Use 持続的 for the general adjectival sense of something continuing steadily, and 「息の長い」 when praising an effort or work that lasts a long time.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 持続的じぞくてきcontinuous
• 息の長いいきのながいlasting (work)