To max out your gains, you may want to do less work in the gym, experts say.
"Junk volume" refers to exercise that doesn't improve strength or build muscle, wasting your time and energy, Jeff Nippard, a bodybuilder, powerlifter and fitness coach, said in a recent video on his YouTube channel.
"I personally think it's holding many trainees back from getting the gains that they want," he said.
Junk volume can include working out for too long, or doing large sets with light weights, according to Nippard. It can be a problem for both newbies and elite athletes, stalling progress and increasing injury risk.
To avoid muscle-building plateaus and to get the most out of your routine, plan your workouts to make every rep count, experts and evidence suggest.
Doing too many reps or sets can backfire
Research shows that for building muscle and strength, more work doesn't always lead to more gains.
About six sets per session per muscle group is a good baseline for maxing out on benefits, according to a 2017 study Nippard cites. After six, the benefits then appear to plateau, and working more will eventually lead to smaller and smaller additional gains, the research indicates, although muscle response can vary in different people.
So, while you might be trying to boost your progress with more work, the additional benefit of the last few sets is small enough to be insignificant, and unlikely to be worth the time and effort, Nippard said.
As little as two sessions per week per muscle group can be effective, other evidence and experts suggest.
Lifting too light can waste your time, too
Junk volume also includes wasting your effort by not lifting heavy enough, according to Nippard.
One of the most common mistakes is doing "easy sets" that end before you've challenged your muscles enough to grow, he said.
Research has found many people underestimate how much they can lift, and often end up finishing a set with six or more reps in reserve. While you don't need to lift to failure on each setting, getting within a few reps of failure can maximize your muscle activity to improve gains, evidence suggests.
Another pitfall is lifting very light weight for high reps (30 or more), based on the myth that it can help "tone" a muscle without making you bulky.
While light weight or bodyweight exercise can build muscle, lifting less than 20% of your maximum effort can stall gains, research shows, even if you're sore after.
"It can get you super sore and impair your performance for future workouts, but end up compromising your result despite actually working harder," Nippard said.
If you're doing more than 30 reps, you'd be better off lowering the number and increasing the weight, Nippard said.
Pressure to look lean can prompt overtraining
Doing junk volume can be caused by anxiety about looking and performing your best, CrossFit athlete Bethany Shadburne told the Morning Chalk Up.
Shadburne said she's a "recovering over-trainer" and realized junk volume was hurting her progress and leading to injury. She now takes a "less is more" approach to the gym (which earned her a second place in the elite Wodapalooza competition in January).
Shadburne said women can be particularly vulnerable to overtraining because of intense pressure to appear lean or to avoid gaining body fat.
"Am I doing this extra rep or this extra set because of those reasons or is it actually going to benefit me?" she said. "It's an everyday battle when I come into the gym to not do extra work."
