Anything we do involving novelty, variety, and challenge stimulates the brain and can contribute to building capacity and brain reserve. For instance, learning how to play the piano activates a number of brain functions (attention, memory, motor skills, etc.), which triggers changes in the brain itself (this is called "brain plasticity"). Indeed, musicians have larger brain volume in areas that are important for playing an instrument: motor, auditory and visuospatial regions. However, such an activity may take thousands of hours before paying off in terms of brain fitness. It constitutes a great and pleasurable mental effort, and helps build cognitive reserve, but it is different by nature from more targeted, efficient, and complementary brain training interventions.