Manual jobs are very good for fitness

Hi! I recently started a job where basically my main duties are to receive deliveries and place them into our storage and to generally help with cleaning, prepping food, moving stuff etc. One of these duties for example involves moving several 25 kgs flour's bags down the stairs and place them on the shelves. I started one month ago and physically I'm feeling great, I can see clear changes in all my body and often I feel like I've been working out. I know it sounds crazy, mainly because this particular kind of manual jobs are often considered poor (wage is shit, yeah), but I think manual jobs are actually a decent alternative way to improve your body if you can't go to the gym for some reason.