Frequently asked questions
How do I measure my wrist circumference correctly?
Use a flexible tape measure (or a string you later measure). Wrap it around the narrowest part of your wrist, just below the wrist bone (the bony bump on the pinky side). Keep the tape snug but not compressing the skin. Measure in the morning before exercise, as wrists can swell slightly during the day.
Why does frame size matter for ideal weight?
Standard ideal weight charts assume a medium frame. A large-framed person naturally carries more bone and muscle mass, so their healthy weight is higher than the chart midpoint for their height. A small-framed person is healthier at the lower end. Frame size can shift ideal weight by 5–10%.
Can I change my body frame size?
No. Frame size is determined by bone structure, which is genetic and fixed after growth plates close (typically by age 18–21). You cannot make your wrists, ankles, or overall skeletal structure smaller or larger through diet or exercise. What you can change is muscle mass and body fat.
Is the wrist method accurate?
The wrist measurement is a simple, well-established proxy for overall skeletal size because the wrist has very little fat or muscle to distort the reading. It is used in the Metropolitan Life Insurance height-weight tables and is endorsed by the National Institutes of Health as a quick frame-size indicator.
Does body frame size relate to somatotype (ectomorph, mesomorph, endomorph)?
They overlap but are different concepts. Frame size is purely skeletal (bone thickness). Somatotype also considers muscle tendency and fat distribution, which are partly genetic and partly trainable. A small-framed person is often ectomorphic, but someone can have a large frame and low muscle (not mesomorphic).
Should I use frame size when calculating BMI?
BMI does not account for frame size, which is one of its limitations. If you have a large frame and your BMI is at the high end of 'normal' (24–25), you are likely fine. If your BMI is 'overweight' but you have a large frame and visible muscle, body-fat percentage is a better metric for you.