Did you know partial ranges of motion reps are equal to full range of motion (ROM) reps? Most experts have long held that partial repetitions provide no benefit to the serious weightlifter. However, a study done at the University of Southern Mississippi compared using partial ROM repetitions and full ROM repetitions in the development of strength in untrained males. As far as the development of maximal strength was concerned, partial and mixed repetitions were found to be equally as effective as full repetitions.
This study was conducted over ten weeks and used the bench press as the criterion for measurement. Researchers divided fifty-six subjects into three groups: the first group used three full ROM sets; the second group used three partial ROM sets; the third group used a combination. The researchers found no differences between the three groups. However, they do point out that this study does suggest partial reps can be a benefit to a person’s maximal strength. (J Strength Cond Res.2004;18(3):518-521, )
Does this mean partial reps should be the primary component of a strength training routine? No. As with all studies concerning progressive resistance training, there were too few subjects, and the length of time involved was too short in duration. However, there may be a case in this study for support in using partial reps in addition to a traditional strength training program. Partial reps may work for powerlifters and other athletes who have sticking points at certain points of a lift, e.g., locking a weight out at the top portion of a bench press. Powerlifters have known for some time about the benefits of partial reps and other methods of training weak links simply through trial and error.