Study #2: Heavy Mettle
All the volunteers in Schoenfeld's study did sets of 8 to 12 reps, with 90 seconds' rest in between. A study published this month in Physiological Reports went a different direction: One group of experienced lifters did four sets of 10 to 12 reps, resting 60 seconds in between, while the other did four sets of 3 to 5, using much heavier weights and resting 3 minutes. All of them did the same exercises in the same order.
It's hard to imagine doing lateral raises, barbell lunges, and triceps extensions for low reps with heavy weights. Doing barbell and dumbbell curls for low reps seems a little more natural—the barbell curl was a contested lift in the early days of powerlifting—but it's still not something you see very often.
The surprising result: Those doing the heavy curls and extensions increased their upper-arm mass by 5.2 percent in eight weeks, compared to 2.2 percent for those using the more traditional rep range.
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Study #3: Subtraction by Addition?
For the final study, which appeared in Applied Physiology, Nutrition, and Metabolism, a Brazilian research team had experienced lifters work their upper bodies four times a week for eight weeks. One group did a mix of presses, rows, pushups, and pulldowns, while the others did those exercises plus two more: triceps extensions twice a week, and curls the other two days.
All of them did three sets of every exercise in every workout, but varied the intensity. The first two weeks they did 10 reps per set. Then in the third week they did "shock" workouts, adding forced reps. They cut the weights by 50 percent the following week, and then repeated that cycle for the final four weeks.
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Again, there was a surprising result: Both groups gained upper-arm size (about 1.5 percent when flexed) and strength (5 to 6 percent for curls, 10 percent for extensions), but neither group did significantly better than the other. In other words, there was no measurable benefit from adding arm exercises to challenging upper-body routines.
