Browse evidence-based analysis of health-related claims and assertions
The more the biceps stretched during the first workout, the more 'swelling' showed up on the ultrasound scan afterward.
Correlational
Even though guys lifted the same total weight, those using barbells felt way more sore in their triceps for longer than those using dumbbells—suggesting barbells might be harder on the back of the arm.
Causal
After doing heavy leg workouts, the muscles of trained men show a big spike in two specific proteins (IGF-IEa and MGF) that help repair muscle damage, and this spike happens about two days later.
The more the biceps stretched during the first tough workout, the more strength the person lost the next day.
After a tough chest workout, guys using barbells or machines feel sore in their triceps for a few days, but those using dumbbells don’t feel any soreness at all—even though they lifted the same total weight.
People feel less sore after doing the same tough arm workout a second time, four weeks later.
When trained men do different types of chest presses—using a machine, barbell, or dumbbells—their chest muscles and shoulder strength bounce back at about the same rate after a tough workout, no matter how stable the equipment is.
The second time people do a tough arm workout, their muscles show less 'swelling' on ultrasound scans, meaning there's probably less damage or inflammation.
After doing a hard arm workout twice, four weeks apart, people feel stronger sooner the second time—even though they did the same amount of work.
When people who don't normally lift weights do a tough arm exercise twice, four weeks apart, their biceps don't stretch as much the second time, even though they're trying just as hard.
The pause method doesn’t make your muscles more sore the next day or two after your workout than the normal heavy-lift method.
Quantitative
Even though both methods make your triceps the same size after a workout, the pause method makes the ultrasound image look more 'fuzzy' — meaning something inside the muscle changed differently.
Whether you lift heavy without pausing or lift lighter with pauses, your chest muscles swell the same amount right after the workout.
Even though you do more reps and keep your muscles under tension longer with the pause method, your body doesn’t produce more lactic acid or muscle damage markers — meaning intensity matters more than total reps.
Mechanistic
After either workout method, your muscles stay swollen for three full days — meaning your body is still responding to the stress long after the workout ends.
Descriptive
When you pause at the bottom of the bench press, your shoulder muscles work harder and swell more than your chest or arms — meaning your body shifts the work to your shoulders.
Adding a one-second pause at the bottom of each bench press doesn’t make your muscles more damaged or sore the next day than lifting heavy without pausing.
You can lift almost a third less weight using the pause method, but still do the same total amount of work — and even do more reps and keep your muscles under tension longer.
Even though both methods make your triceps swell the same amount, the pause method causes more 'haze' on the ultrasound image of your triceps muscle — suggesting different internal changes.
Even though the pause method makes you do more reps and keeps your muscles under tension longer, it doesn’t make your chest or arm muscles puff up more than the normal heavy-lift method.
Both workout methods make your muscles equally sore the next day — neither one leaves you feeling more achy than the other.
Both the pause method and the heavy-lift method cause the same amount of muscle cell leakage into the blood after a workout — meaning neither one causes more muscle damage than the other.
Even though one method uses lighter weights with pauses and more reps, and the other uses heavier weights with fewer reps, both make the muscles equally tired in terms of lactic acid buildup.
Both the pause-and-lift method and the normal heavy-lift method cause the same amount of muscle puffiness right after a workout in trained guys — neither one makes the muscles look or feel more swollen than the other.