She took Girls on the Run last year and loved it, but we missed sign-ups this year.
DD age 6 is in dance (a triple class with ballet, tap, jazz) and plays soccer on Saturdays in the fall and spring. She is also in Daisies.
She is not loving soccer so probably won't be signing up next year.
Oldest started dance at age 5 and I could not understand how anybody would start their kids any younger than that. Then I had youngest, and I understood. She wanted to dance and begged to dance with her sister all the time. She started her own dance class at 2 1/2 years old.
I think the quantity of extra-curriculars is an individual thing and whatever works for your family is great.
I am happy with the girls in dance one night per week. Oldest plays viola but her lesson is in the mornings before school twice per week. Daisies is only one night every other week. This is about our limit. Youngest has to go with her dad on Wednesday evenings and every other weekend. Oldest has counseling once per week, or every other week, so this leaves us very few low-key evenings.