Fig. 3

The relationship between muscle fitness indexes. A-1: relationship between GS and VJ in boys; A-2: relationship between GS and VJ in girls; B-1: relationship between GS and SR in boys; B-2: relationship between GS and SR in girls; C-1: relationship between VJ and SR in boys; C-2: relationship between VJ and SR in girls. GS: hand grip strength; VJ: vertical jump; SR: sit-and-reach