Ninety-one subjects were tested to determine the number of repetitions they could perform at 40, 60, and 80 percent of one repetition maximum (percent 1 RM) for each of seven specified weight training lifts. Thirty-eight subjects from a previous study (18) were also included in the data analysis. The subjects represented four categories: untrained males (n = 38), untrained females (n = 40), trained males (n = 25) and trained females (n = 26). The results indicated that there was a significant difference (p < 0.05) in the number of repetitions that males and females can perform at the selected percent 1 RM among the seven weight training lifts, as well as in the number of repetitions performed at these percentages across lifts. When comparing untrained and trained males, a significant difference (p < 0.05) was found in the number of repetitions performed at all selected percent 1 RM for the arm curl, knee extension and sit-ups. Significant differences (p < 0.05) were also found at 60 percent 1 RM for the leg curl and at 60 and 80 percent 1 RM for the lateral pulldown. No significant differences (p > 0.05) were found for any percent 1 RM for the bench press and the leg press. When comparing untrained and trained females, a significant difference in performance (p < 0.05) was found among all seven lifts at 40 percent 1 RM. Significant differences (p < 0.05) were found at 60 percent 1 RM for the knee extension, bench press, sit-ups, leg curl and leg press; and at 80 percent 1 RM for the bench press, sit-ups and leg press. The findings of this study indicate that a given percent of 1 RM will not always elicit the same number of repetitions when performing dafferent lifts.
(C) 1990 National Strength and Conditioning Association