Adrenaline increases the "alertness" of the nervous system, meaning it's ready to trigger muscle contraction. It also ...

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 ...

Anxiety may sometimes cause any of your muscles to start twitching. It may be caused by neurotransmitters being released. Treating anxiety is the best way to prevent anxiety twitching. Twitching is ...

When you picture different athletes—marathon runners, gymnasts, and Olympic weightlifters, for example—you likely categorize them instinctively by their height, size, and build. But the differences in ...

Building your fast-twitch muscle fibers can help you get stronger and faster. This type of muscle fiber is responsible for the fast, explosive movements used in activities like sprinting, jumping, and ...