Comment by vmg12

It would take a lot of different drugs to simulate what exercise does.

- Impact and stress strengthening the muscles, bones and tendons / ligaments

- energy use that leads to better sleep

- increased blood flow, development of new capillaries, stretching of blood vessels

- if you exercise outside, exposure to sunlight

- the release of all the associated neurochemicals

I have a suspicion that anything designed to mimic exercise would hurt as much as the actual thing given that so many of the benefits of exercise involve damaging bone and tissue then repairing it