decondition

de·con·di·tion  (dkn-dshn)

v. de·con·di·tioned, de·con·di·tion·ing, de·con·di·tions

v.tr.

1. Psychology To cause (a conditioned response, such as a phobia) to become extinct.

2. To cause to decline from a condition of physical fitness, as through a prolonged period of inactivity or, in astronauts, through weightlessness in space.

v.intr.

To lose physical fitness.