[sctb]

Strictly speaking, any intervention other than exercise is going to give you a subset of the total stimulation. A drug acting on the tissues directly would bypass the neurological component, for example.

If the idea is to avoid the effort of exercise, perhaps it would be worth considering the possibility that the effort itself is essential.

[Bnjoroge]

not entirely true. you can have drugs that directly act on the respective receptors, either inhibit or excite them.

[maccard]

If we were good enough to have drugs that could work with that precision we’d eliminate an enormous category of things. The side effects are usually the scary things. We have drugs that can cure the symptoms of depression and anxiety - they just so happen to be insanely addictive, cause respiratory depression, loss of coordination, and you quickly build a tolerance to them.