Keira has noticed that her fitness group used to work as hard as they could on reaching their goals but now they seem to treat the group more as a social club. She wants group members to get more focused on fitness what word best describes the area Keira wants her group to improve.

The word that best describes the area Keira wants her group to improve on is "diligence." Diligence refers to the careful and persistent work or effort. By encouraging diligence, Keira is emphasizing the importance of consistent and earnest efforts toward achieving fitness goals, rather than just socializing during group activities. She wants her group to refocus their attention and efforts on working out diligently to reach the fitness objectives they originally set out to achieve.