Muscular Strength And Power In Children 3-7 Years Old

Abstract

Muscular performance of many types have been determined for adults and post-pubescents. Few data exist concerning muscle kinetics and kinematics for prepubescent children. PURPOSE The purpose of the present study was to determine absolute and relative (adjusted for body mass) strength, mean power, and mean velocity for upper and lower body resistance exercises in young boys and girls. METHODS Boys and girls (ages 3–7 yrs) were tested for 1 repetition maximum (1 RM) strength for the chest press and leg press exercises. Weight machines were modified to accommodate the smaller dimensions and lower strength levels of the children. An external dynamometer (Fitronics; Bratislava, Slovakia) was interfaced with the machines and loads were set at 70% 1 RM to determine mean power and mean velocity. The effects of gender and age were determined via ANOVA (p ≤ 05). RESULTS No gender differences were observed for any variable at any age. 1 RM strength, mean power, and mean velocity sig. increased across ages. With one exception, these increases disappeared when results were adjusted for body mass. Relative mean velocity actually decreased for the leg press exercise. Test data indicated children from 3–7 yrs are capable of performing strength and power tests, but may require more attempts than adults, and may need to attempt maximal loads more than once. CONCLUSION These results provide the first data on muscular strength, power and velocity in very young children. Gender differences were not apparent for these ages. Muscle strength and power was associated with increasing body mass, while relative velocity actually decreased in a manner similar to the decreasing body mass index. It appears that muscular strength and power during this stage of development are primarily dependent on increasing body mass, whereas velocity is influenced by additional variable(s), perhaps the increases in stature during these ages. In this age range, it appears that forcerelated variables are dependent primarily on size.