Agents which are naturally talented in Psionic skills need to train hard to maintain and improve their power, attack and defense. The Psi-Gym is equipped with the latest Psionic technology and Psionic training is not possible without such a facility. Agents assigned to Psionic training will automatically use any Psi-Gym at a base, but if the capacity of the gyms is exceeded then training will not take place at 100% efficiency. From: Apocalypse Ufopaedia
A Psi-Gym is used to train psionics.
training learning within the Psi-Gym cannot use the Training facility. An injured agent cannot use the Psi-Gym until recovery is complete. Maximum learning is complete when psionic attributes have tripled from their original values.
Androids cannot use the Psi-Gym.