Building a defined back and strong arms not only enhances your look but is also key to maintaining an elegant posture, preventing injuries, and feeling more energetic every day. Let's dive into the ...

Thanks to a strain that’s left her sidelined for weeks, all eyes are on Caitlin Clark’s quad right now. But it’s the Indiana Fever star’s arms that had people talking in the days leading up to her ...

Beth Skwarecki is Lifehacker’s Senior Health Editor and has been writing about health, fitness, and science here since 2015. Beth was the recipient of the 2017 Carnegie Science Award in science ...

Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

People are fangirling over Caitlin Clark's arms. (Photo Illustration: Anna Pers Bräcke for Yahoo News, photo: Getty Images) Thanks to a strain that’s left her sidelined for weeks, all eyes are on ...