So you're working out and you keep looking at your watch at the top of every biceps curl. Sure, you want to finish your routine, but you've got to get to the next thing in your life. And you wonder: What if you just did one set of strength exercises rather than the almost universally prescribed two or three?
Well, we know you hate it when we say this, but . . . it depends.
If you're a novice who has just begun a program, a single-set routine will do the trick. The bad news: After about three months -- or perhaps as much as a year, depending on whom you ask -- you're likely to hit a plateau.
"If that [basic] level of fitness is all you want . . . you can maintain [it with single sets], but you aren't going anywhere," said William Kraemer, an exercise physiology professor at the University of Connecticut and an American College of Sports Medicine (ACSM) expert on resistance training.
Kraemer cited numerous studies in peer-reviewed journals over the past three years, including ACSM's journal Medicine & Science in Sports & Exercise, that show initial strength gains for previously untrained men and women who do single-set routines, followed by flat-lining at around three months. Multi-set lifters showed steady gains in strength after that point.
"Multiple sets causes greater breakdown [of muscle fibers] and greater repair," Kraemer explained. It's this process of breakdown and repair of muscle tissue that leads to strength gains and muscle growth. Kraemer co-authored ACSM's 2002 position paper on progressive resistance training, which calls for multiple sets for non-novice lifters.
Matthew Rhea, assistant professor of exercise science at Southern Utah University, in Cedar City, Utah, has done extensive research on this topic.
"There is some evidence that [an exerciser] could continue to realize very slight strength gains from single-setting after a year or even two. But most likely [that person] will simply maintain strength," he said.
Based on a meta-analysis of more than 200 studies, he said, there is scientific support for gains from single-setting. But the more trained you are, the smaller those gains appear to be, he said.
Wayne L. Westcott, fitness research director at the South Shore YMCA in Quincy, Mass., is more sanguine on the single-set theory. Widely published in the field, he says he's seen gains from a single-set program continue for a year or more. Once you plateau, he said, try this modification: Do your eight to 12 reps to failure, then immediately reduce the weight (from, say, 100 pounds to 80) and squeeze off another four our five reps to failure. By extending the single set with extra reps, you'll produce gains, he said.
Kraemer offered another tactic for gym-goers who dread the standard three-sets-of-eight-to-12-reps: "There is no rule that every exercise has to be the same number of sets." For example, you could do three sets of bench presses, which involve multiple muscles, but only one of biceps curls, which benefit just the biceps. If you are time-pressed at the gym, focus on the larger muscle groups -- quads, chest and back -- because exercises for those muscles also recruit smaller muscles nearby, like hamstrings, biceps and shoulders.
The good news is, you'll know if you flat-line. "No matter how you lift, you can judge progress by how much more weight you can lift over time," Westcott said. A beginner may see a 40 percent gain in the first 12 weeks, 20 percent over the next 12, then a 10 percent gain, then five. Gains will slow and stop as you near your potential, regardless of set number.
So the consensus of experthood: Single sets are good for beginners and useful for maintaining strength. Two sets are better for boosting strength, and three sets better still. And of course, Rhea said, "one set is better than nothing" for any lifter.
But you knew that. No chat this week, but we return online next Thursday at 11 a.m. Want to reach us sooner? The e-mail is firstname.lastname@example.org.
-- John Briley