This is the 9919th most frequent Russian word.
активностью
The Russian word "активностью" means "activity" (instrumental case).
emphasizing the quality or trait of someone's behavior as being active
Её активностью восхищаются все друзья.
Her activity is admired by all her friends.
describing the approach to an action or task with vigor and involvement
Нужно подойти к задаче с полной активностью.
You need to approach the task with full activity.
referring to the actions or efforts demonstrated by someone, in this case, athletes