Health Claims

In trained men, performing elbow curls with the arm in a backward or forward position, using light weights and restricted blood flow for three weeks, leads to nearly identical muscle growth in the...

Because portable ultrasound measurements of muscle thickness vary too much between technicians, it should not be used alone to diagnose muscle loss in older adults.

When measuring fat located deeper in the abdomen, portable ultrasound shows slightly less consistency between different technicians, with agreement slightly lower than for fat just under the skin.

Portable ultrasound can measure muscle thickness in older adults with moderate to good consistency, but results vary depending on the body site and technician, making it less reliable than for fat...

Portable ultrasound devices can consistently measure the thickness of fat just under the skin in older adults, with very little variation between different technicians taking the measurements.

Ultrasound often has a measurement error of over 10%, which is as large as the muscle growth expected from 3 months of training—meaning you can’t be sure if a small increase is real growth or just...

Ultrasound readings can consistently be too high or too low due to factors like when you scan, how hydrated you are, or how the operator holds the probe—these consistent errors aren’t fixed by saying...

How much muscle growth you can reliably detect with ultrasound depends heavily on how you analyze the data—using the best scan might make growth look easy to detect, but using the worst scan shows...

Commonly used reliability scores like ICC make ultrasound look more accurate than it really is because they ignore consistent measurement errors and random noise—meaning a small change in muscle...

Ultrasound can measure muscle thickness with varying degrees of error—sometimes as high as 20%—depending on how the scan is performed. These errors can be larger than the actual muscle growth...

Training biceps with the arm fully stretched or with a mix of positions doesn't make you feel more sore or more tired afterward, as long as the total effort and volume are the same.

Measuring arm size with a tape measure can show increases that don't reflect actual muscle growth — they might just be from swelling, fat changes, or measurement error.

Whether you train biceps with full arm stretches or a mix of stretches and bends, you get about the same strength gains in both fully stretched and bent positions, as long as you do the same number...

Training biceps with the arm fully stretched or with a mix of positions doesn't make one part of the muscle grow more than another, as long as the total workout effort and volume are the same.

For people who regularly lift weights, training biceps with the arm fully stretched or with a mix of stretched and bent positions leads to about the same amount of muscle growth and strength gain, as...

Even though the biceps muscle is stretched more when the arm is behind the body during curls, this does not lead to greater muscle growth compared to when the arm is in front — suggesting passive...

You can build arm muscle effectively using light weights if you restrict blood flow during exercise, even without lifting heavy loads.

When training the biceps with light weights and blood flow restriction, muscle growth occurs evenly along the entire length of the muscle, not just near the shoulder or elbow.

Using light weights with blood flow restriction for three weeks causes measurable growth in the biceps and related arm muscles, regardless of whether the arm is positioned in front or behind the body...

When performing low-weight arm curls with blood flow restriction, training with the arm behind the body (lengthened muscle) produces the same muscle growth in the biceps and related muscles as...

When people train with light weights and a pressure cuff for three weeks, their muscles grow even if they don’t change what they eat—meaning the training itself, not diet, is responsible for the...

Stretching the biceps by holding the shoulder back during light arm curls with a pressure cuff doesn’t make the muscle grow more than keeping the shoulder forward—passive tension from stretching...

When training the biceps with light weights and a pressure cuff, the muscle grows at roughly the same rate along its entire length—from near the shoulder to near the elbow—without favoring one part...

Using light weights with a pressure cuff on the upper arm for three weeks can make the biceps and related muscles grow by about 4% to 8%, even without lifting heavy weights, and this growth happens...