The following is an excerpt from 2 x 4: Maximum Strength
Many programs utilize percentages for loading schemes. To name a few, Shieko, Smolov, and The Russian Squat Routine each provide the lifter with detailed set and rep schemes based off of percentages of 1RM. For example, a particular training day might have the lifter performing 7 sets of 5 reps with 80% of 1RM. These types of programs are very convenient as they take all of the guesswork out of the equation and allow the lifter to get in and get the job done.
Sounds incredible in theory, right? Problem is, programming just isn’t that simple. My colleague Brad Schoenfeld and I recently collected data for an upcoming study we intend on publishing that examines the EMG activation in the leg muscles with heavier weight (75% of 1RM) versus light weight (30% of 1RM) to failure. While we weren’t particularly interested in the number of repetitions the subjects achieved during exercise performance, we were intrigued to find that with the 75% of 1RM loading, the ranges of repetitions achieved by the subjects varied dramatically from one lifter to the next. While most subjects performed between 10 and 15 repetitions, one subject performed a whopping 21 repetitions, and another subject performed just 7 repetitions (with 30% of 1RM, the range was 30 to 71).