Which word refers to the active strength of the body or mind?

The word "vigor" refers specifically to the active strength and energy of both the body and mind. It denotes a sense of liveliness, vitality, and the ability to engage in vigorous activity. While "energy" can imply a general capacity for activity, it is broader and can refer to various forms of energy, not just physical or mental strength. "Strength" primarily indicates physical power or ability rather than the combined notion of mental and physical vitality. "Stamina" is more closely associated with endurance over time, particularly in physical activity, rather than the overall active strength that "vigor" conveys. Thus, "vigor" effectively captures the essence of active strength across both realms.