The difficulty level of fitness. K 1 Introduction, K2 Elementary, K3 Intermediate, K4 Advanced. Choose according to your own amount of exercise and physical condition. The grades of k 1, k2, k3 and k4 in KEEP are suitable for people with different physical qualities. Pamela k 1k2k3 is the difficulty level of fitness. Pamela is a fitness blogger, Pamela is also an aerobics enthusiast, Pamela is a very beautiful fitness expert, and she often shares various videos such as aerobic exercise and self-weight strength training.