Sports and exercise are definitely beneficial, but any sort of activity presents a risk of injury.

If people work out, or play sports, without knowing proper form, without using protection or precautions, they'll get injured and then worse off than before. Realistically, manual laborers should be in real good shape, but often their jobs are so low-wage, and they're so interchangeable, that safety precautions are ignored and must be regulated/enforced.

I took up roller skating and was rewarded with a broken leg. I took up gym exercise and was repaid with a hernia. Both required surgery. No regrets! Only wished I could've better understood how to exercise safely!

I once encountered a FB group that was for people to discuss "sports injuries sustained while we were in bed" and I could totally relate, having done weird stuff to my shoulder overnight, rather than pitching a baseball game...