I was a regular at sports gyms for 15 years until three years ago.
Until three years ago, I went to the gym regularly for 15 years.
I was a gym goer for 15 years until three years ago.
英訳1:「常連」はregularと言います。「〇間」は for、「~まで」は untilで表現できます。
英訳2:go to ... regularlyで「…によく行く、定期的に行く」という意味です。
英訳3:goerにも「よく行く人」という意味があります。
その他の言い方:
- Until three years ago, I frequented sports gyms for 15 years.
- Up until three years ago, I was a gym goer for 15 years.
- I had a gym membership for 15 years until three years ago.