Browse evidence-based analysis of health-related claims and assertions
When trained guys use the 'zero point' bench press technique, their shoulder muscles swell more right after the workout than when they use the normal method — but their chest and arm muscles swell the same either way.
Quantitative
When trained guys lift lighter weights but pause briefly at the bottom of each bench press, they can do more reps and keep their muscles under tension longer than when lifting heavier weights without pausing — even though the total weight lifted stays the same.
When counting how much you lift, giving partial credit to exercises that work multiple muscles at once (like squats) gives the most accurate picture of your training load.
The math used in this study shows it’s almost certain that more lifting leads to more muscle and strength, and more frequent workouts lead to more strength—but not necessarily more muscle.
Most of what we know about how much to lift and how often comes from young men who already work out—so we don’t know if it works the same way for women, older people, or beginners.
Descriptive
Even if you lift the same total amount each week, spreading it across more days can still make you stronger—frequency matters on its own.
Correlational
More lifting helps, but only up to a point—after that, each extra set gives you less and less benefit, no matter if you’re trying to grow muscle or get stronger.
If you want to get stronger, doing your workouts more often helps—more than if you just want to get bigger muscles.
When counting sets that work multiple muscles at once, giving them half credit (instead of full or zero) makes predictions about muscle growth and strength more accurate.
Most of the research on how much to lift and how often was done on young men who already train—so we don’t know if the same rules apply to women, older people, or beginners.
How much you lift in total each week matters more for results than whether you do it in 2 days or 5 days—unless you’re trying to get stronger, then frequency helps a bit.
Training more often helps you get stronger, but doesn’t seem to help you get bigger muscles—so frequency matters more for strength than for size.
Muscle size and strength don’t respond the same way to more training—strength peaks faster, so adding more sets helps muscle growth longer than it helps strength.
Not all sets count the same—sets that directly target the muscle you're measuring matter more, and a method that gives partial credit to indirect sets works best for predicting results.
Spreading your workouts across more days per week can help you get stronger, but after a certain point, adding even more days doesn’t help much more.
Doing your workouts more often per week doesn’t seem to help you build more muscle, as long as the total amount of lifting stays the same.
Lifting more weights each week makes you stronger, but the extra strength you gain from each additional set gets smaller faster than the muscle gains do.
Doing more sets of weightlifting each week helps you build more muscle, but after a certain point, adding even more sets gives you less extra benefit.
When trained guys do lots of reps, they feel more tired, weaker longer, and more stressed than when they do fewer heavy reps — even though their muscles are damaged about the same.
Causal
Even after a tough workout, your body doesn’t show signs of widespread inflammation in the next few days.
One workout, whether heavy or high-rep, doesn’t change your testosterone levels in the hours after.
Your muscles don’t get bigger or smaller right after a single workout, no matter how hard or how many reps you do.
Pulling or squatting as hard as you can from a static position doesn’t get weaker after either type of heavy lifting session.
Lifting heavy weights just a few times doesn’t stress your body as much right after as doing lots of lighter reps.