Manual of Gainful Exercise

Manuals of Gainful Exercise are magically tomes that increase the primary ability of strenght by one point and are consumed when the point is added. One tome  can be found in the Underground passages of Candlekeep.

In-game description
"A typical manual of gainful exercise provides the reader with strictly regimented routine of daily stretches and tests designed to increase muscle bulk. As if this isn't enough, the manual is also magically enhanced, thereby allowing an individual to raise his or her Strenght by a single point. Unfortunately, the manual will dissappear after a single use."