This really depends on the issue. If, for example, you have a mobility issue, and walking directly hurt the mobility issue, then the solution is physio or massa

This really depends on the issue. If, for example, you have a mobility issue, and walking directly hurt the mobility issue, then the solution is physio or massage to resolve the mobility issue. But for your more garden variety “I am tired and my joints hurt” then exercise tends to be a virtuous circle. You push yourself to do a little, and it is rough, but it improves the body’s capacity. Then you feel a bit better later and can do more. Being unhealthy is an equilibrium, and you can push yourself into a better equilibrium with exercise, food and sleep. For 90% of people reading this what I wrote will be true. But you may be in the 10% where you have an underlying issue to fix first, so check with a physio and a doctor.