There are multiple things being lumped together. The body constantly heals itself, but doing blue collar work the issue is that the cumulative load regularly ex

There are multiple things being lumped together. The body constantly heals itself, but doing blue collar work the issue is that the cumulative load regularly exceeds your recovery ability. Athletes can stay under the limit if they are careful. Irrespective of job or sports people can randomly develop degenerative diseases as they age that can be exacerbated by work.