Do people who do physical labor tend to have muscular builds?

‌Back when I used to go to the gym in middle and high school, I saw many middle-aged men who were self-employed, vegetable vendors, or construction workers (this is just a guess) who showed up consistently and had great physiques.
Are there still many people like that these days?
I used to see many muscular older men with faces that showed the traces of their life, but with solid, well-built bodies that looked like they had been exercising for a long time.