How do I keep doing hard physical work that my body may not survive to retirement?

There is a hard truth in your trade: you build things meant to outlast you, while the building wears your body down. Holding both of those at once is heavy. It is right to take the worry about your body seriously, because it is the one tool you cannot replace. So treat it like the valuable tool it is. Protect it now, not later. The way you lift, the rest you take, the pain you stop ignoring, the doctor you finally see. Small habits today decide whether your body reaches the finish line you are working toward. This is not weakness. It is the smartest long-game move you can make. And do not let retirement be the only reason you keep going. If the whole point sits decades away, the punishing days feel pointless. Find something in the work now, the pride of a job done right, the mark you leave. Care for the body, honor the craft, and take it one solid year at a time. That is how bodies and careers last.