Old age is characterized by an age-related cognitive decline. The role of executive functions in this process has recently been indicated. The population of elderly people, however, is not homogenous in terms of intellectual functioning. This diversity may be explained by evoking the notion of cognitive reserve which posits that elderly people have different levels of resources enabling them to compensate for the negative changes. The level of the cognitive reserve is related to the level of the executive functions. This study analyzes the relationship between the levels of three components of the executive functions: flexibility, working memory and planning, and educational, cultural or physical activities carried out throughout life. The results show that educational and cultural activities are important to working memory, while planning is additionally helped by physical activity. Further, some components of the executive functions are more influenced by activity before retirement, while others are more affected by activity after retirement.