Shop › Core Challenge - 10 Day/Beginner Image 1 of 2 Image 2 of 2 Core Challenge - 10 Day/Beginner $2.50 Complete 3 different core workouts per day for 10 days. Add reps and weights to level up. Add To Cart Added! Complete 3 different core workouts per day for 10 days. Add reps and weights to level up.