Chicken wings habit

I kept the habit of swimming since 2016. Wherever I am, at least once a week, I find a swimming pool and jump in it.
I practice. I work out. Every week, for over a year.
At least 1.5 kilometres every session. It took me 52 minutes to finish all the laps last year, and now I’m down to 45. I learned forward crawl: I do 750 metres breathe stroke, 750 metres forward crawl.
I’m not the fastest person in the water, but I’m in the medium-to-fast lane.
So then.
When will I finally grow a man’s arms instead of these chicken wings?