Adrenaline increases the "alertness" of the nervous system, meaning it's ready to trigger muscle contraction. It also increases the amount of blood flow and changes the tension of the muscles, which, ...

Infectious agents can cause muscle twitching and spasms, too. The most commonly known is probably tetanus, which causes a phenomenon called lockjaw, where the neck and jaw muscles contract to the ...

Doctors identify these movements as 'fasciculations', because they occur when individual nerve fibers, which control small muscle groups activate independently to produce brief muscle contractions.

After a grueling CrossFit workout on a hot Summer morning that involved kettlebell swings, goblet squats, and about 100 walking lunges, my lower body was toast. But what was weird was that my left ...

Fast-twitch fibers help with explosive movements like sprinting and weight lifting. Genetics and training influence the distribution of fast-twitch and slow-twitch muscle fibers. Doing strength ...

Caroline Roberts writes articles and notifications for CNET. She studies English at Cal Poly, and loves philosophy, Karl the Fog and a strong cup of black coffee. Have you ever set out in earnest to ...

Many things can cause your thumb to twitch, from lack of sleep to autoimmune conditions. If it continues for more than a few days or occurs with other symptoms, you may need medical care. Thumb ...

Twitching at night—it’s something few of us talk about, yet it’s also a phenomenon that impacts Americans when it comes to sleep quality. And even if you feel like you’re getting enough sleep, you ...