There is so much mythology around exercise and especially around weight training. I’ve recently resumed weight training after a back injury a few months ago spurred me to get stronger. Because I am a major nerd, I read about six books on weight training.
What I learned was that to get stronger you needed to do multiple sets of each exercise. Let me explain for those of you that are not savvy about weight training. Let’s say you decide to work out your bicep muscle. You pick up a dumbbell that weighs 10 pounds, and you curl it 12 times. Those are called repetitions. Then you rest for a minute or two, and you do 12 more repetitions. So far you’ve done two sets.
Conventional Wisdom on Weight Training
Most of the books I read suggested that it was necessary to do at least three sets, but often five sets in order to develop true strength. Many of the books differentiated between lifting heavy weights fewer times and lighter weights more times. When you lift heavy weights fewer times supposedly you develop more strength and less size, and when you lift lighter weights more times you develop strength but also bigger muscles.
It turns out that there is almost no science about any of this! Thanks to a group of researchers from Australia and from New York, we now have some good research. There is a good article about this research in the New York Times.
The researchers took 34 fit young men who had some experience with weight training. They randomly assigned them to three groups; one group did one set of each exercise per training session, the second group did three sets of each exercise per session, and the third group performed five sets per exercise each training session. A set was 8 to 12 repetitions performed to failure, meaning the person could no longer lift the weight any further.
All groups did three weekly sessions, every other day, for eight weeks. The researchers then evaluated muscle strength by determining the maximum weight that each person could lift using a squat and a bench press exercise. They also measured the size of the participants’ muscles in the arms and the legs.
The one-set group took about 13 minutes to do each workout, the three-set group took about 40 minutes, and the five-set group took about 70 minutes to do one full workout.
Research Study Results:
So what happened? Surely the men who did five sets of each exercise got stronger than the ones who only did one set, right?
Actually, there was no difference in the strength increase between the three groups. All three groups got stronger. The only differences were found in muscle size. The group that did three sets had slightly bigger muscles at the end of the study than the group that did one set. In the group that did five sets had even bigger muscles. But these were muscles that were bigger but not stronger.
This is great news for those of you who want to do weight training but who want to use the minimum effective dose of weight training. Since most of us would like to feel stronger and fitter, and not everyone cares about muscle size, this streamlined workout is equally effective. And one could get significantly stronger spending 45 minutes per week spread over three workouts. (I suspect that two workouts per week would also improve strength.)
If you are interested in taking up weight training, be sure to consult books on weight training, videos on YouTube, and perhaps pay a weight trainer to teach you how to do each exercise with good form. You don’t need a trainer on an ongoing basis, but it’s useful to learn from an expert so that your form doesn’t lead to injuries. Also a trainer can assess your current strength and figure out what weights you should be lifting at first.
I’m off to do my 13-minute weight training session…