What's So Magical about Doing 10 Reps?
Who decided on 10 reps? Why not nine? Why not eleven? Is ten some kind of magic number?
Why did Delorme and Watkins (the original researchers in the area of sets and reps) choose ten? The truth is the three-sets-of-ten idea is based on some very old research that actually established and defined the idea of progressive-resistance exercise and the concepts of repetition maximums.
In case you care, the term repetition maximum (RM), that we see so often referred to in the literature, is the maximum amount of weight you can lift for a specific number of repetitions. In other words, if you can bench press 135 five pounds ten times, then your ten-repetition maximum (10 RM) is 135 pounds.
Progressive resistance is the simple concept that forms the basis for strength training. Basically, you are supposed to try to lift more weight or do more reps every time you do an exercise.
Why does this matter?
Repetition maximums matter because they allow us to track our progress. Keep a journal of your five-repetition maximum (5RM) and ten-repetition maximum (10 RM) for most exercises in your program. Knowing these numbers allows you to gauge your progress. From time to time, try a new ten-repetition maximum or a five-repetition maximum. If you're not increasing either, you haven't been consistent with your workouts, or the workout program you are using is not working.
Here's an amazing thought, courtesy of a writer named Stuart McRobert, author of Brawn: If you are not getting stronger, your program doesn't work. I don't care how often you train. The point of lifting weights is to be able to lift heavier weights. Without progressive increases in resistance, the body will not respond with the visual changes many of us desire. Whether you want to get stronger or look better, or a combination of both, progressive resistance is the key.
Bottom line: Increase the amount of weight you lift or the number of reps you do each week. You can do three sets of nine or three sets of eleven—it makes absolutely no difference. What matters is effort and progressive resistance. Just think about the words "progressive resistance." Progressively increase the resistance and you'll change the way you look and perform.
Michael Boyle is one of the world’s leading experts in the area of performance enhancement and the owner of StrengthCoach.com. He is also the author of Functional Training for Sports.