RELATIONSHIP BETWEEN REPETTTIONS AND SELECTED PERCENTAGES OF THE 1 RM IN 8 TO 13 YEAR OLD CHILDREN

Abstract

837 Although youth strength training is now recognized as a safe and effective method of conditioning for children, the relationship between repetitions and selected percentages of the 1 repetition maximum (RM) in this young population remains unclear. Therefore, we measured the 1 RM strength in 6 boys and 7 girls ([horizontal bar over]x age 10.7 ± 1.7 yrs, weight 45.4 ± 14.8 kg, height 127.9 ± 14.4 cm) on the Heartline chest press (CP) and the Nautilus leg press (LP) exercises. Subsequently, we tested the subjects to determine the maximum number of repetitions that could be performed to failure at 50%, 62% and 75% of their 1 RM for each exercise. Results from the 1 RM and repetition trials ([horizontal bar over]x±SD) are presented in the table below:TableResults indicated that there was a significant difference in the number of repetitions performed on the CP and LP exercises at 50% of the 1 RM. This suggests that a given number of repetitions may not always be associated with 50% of the 1 RM when children perform the CP and LP exercises. Previous sport experiences and each child's willingness to work through his or her“comfort zone” when performing repetitions to failure may explain the variability in repetition scores. While further study is warranted, the results of this preliminary study suggest that a given percentage of the 1 RM(< 62%) will not always elicit the same number of repetitions when children perform the CP and LP exercises.