Browse evidence-based analysis of health-related claims and assertions
When guys who don’t lift regularly do weight training, even doing more sets doesn’t change certain key muscle signals called Akt and mTOR—so those signals must already be maxed out at low workout levels, and something else is driving the bigger changes seen in other muscle signals.
Mechanistic
If untrained guys lift weights on an empty stomach, doing 5 sets of exercise really ramps up a key muscle-building signal in their cells—but just 1 set doesn’t do much, suggesting you need more than a little effort to kickstart muscle growth.
When guys who don’t normally lift weights do a tough leg workout on an empty stomach, their muscles show a big spike in two specific signals that tell the body to build more muscle, and this might mean doing more sets makes those signals even stronger.
Doing more sets, reps, and lifting heavier weights doesn’t always mean you’ll grow bigger muscles—some people see big gains with less volume, while others don’t grow much even with more work.
Correlational
If older women who’ve gone through menopause do more weight training sessions, they tend to gain more muscle mass than those who do fewer sessions.
If you're already experienced with weight training, doing the exact number of sets your past logs suggest (1.2 times your usual) builds more muscle than doing a fixed number of 22 sets every week — and this is shown by measuring your thigh muscle thickness with ultrasound.
Causal
People who already train regularly are more likely to see real muscle growth when their workout plan is customized for them, rather than using a one-size-fits-all routine — and the difference is about half as many more people seeing real gains.
If you adjust your weekly weightlifting routine based on your own workout history, you’ll likely build more muscle in your thigh compared to following a one-size-fits-all workout plan—after 8 weeks, the difference is about the size of a small coin.
Taking breaks from intense workouts every few weeks doesn’t reduce your overall training volume or stop you from building muscle in the long run.
Your muscles grow bigger not because of just one thing like lifting heavy weights or doing lots of reps, but because of how all the workout factors—like how hard you push, how often you train, and how well you recover—work together.
If you push your muscles until they can't do another rep, you create more force per set—which can help if you're not doing many sets, but might hurt your progress if you're already doing a lot of work.
Adding just one or two extra sets of exercise per week probably won’t make your muscles grow any more, because everyone’s body reacts differently and it’s hard to measure tiny changes accurately.
It doesn't matter how you spread out your workouts—what really matters is how much total stress your muscles have been under over weeks or months, just like how your total food intake over time decides if you gain or lose fat.
If you lift weights, your muscles grow bigger — but only up to about 45 sets a week per muscle group; after that, you don’t get much extra growth no matter how much more you train.
Quantitative
Everyone’s body responds differently to workouts—what works wonders for one person might be too much or too little for another, because of differences in genes, energy use, and how fast they recover.
Descriptive
Doing more workout sets might help your muscles grow just a little bit more—even if the difference isn’t big enough to say for sure it’s not just random chance.
Doing more workout volume doesn’t necessarily make your muscles grow more—your body’s internal muscle-building signals stay about the same no matter how much you train.
Doing more sets at the gym than you're used to—like going from 18 to 33 sets a week per muscle group—doesn’t make your muscles grow significantly more, even though you might see a little more growth overall.
Whether someone is older or younger, male or female, doesn’t really change the size of the bony structures inside their nose — so doctors don’t need to worry about age or sex when measuring swollen nasal tissues.
When the wall between your nostrils is bent badly (more than 15 degrees), the fleshy part inside your nose tends to be bigger—but if it’s only slightly or moderately bent, the size doesn’t change much. It’s like there’s a tipping point where things suddenly get bigger.
When people with a crooked septum have swelling on just one side, that one side gets much bigger than when both sides are swollen — as if the body is overcompensating on the blocked side.
When the wall between your nostrils is more crooked, the fleshy parts inside your nose tend to be bigger — and this connection isn't super strong, but it's noticeable.
People with a crooked nasal septum and swollen inner nose tissues have bigger swollen tissues on both sides of their nose than people with just swollen tissues or no issues at all — suggesting that a crooked septum might make the swelling worse.
We’re not sure if the soreness and tiny tears in your muscles after a tough workout actually help your muscles grow bigger—or if they’re just a side effect.