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 ...

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

A muscle spasm — also known as a charley horse, muscle cramp or twitch — is a sudden, involuntary movement in one or more muscles. Common causes include stress, exercise, or dehydration, but nerve ...

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 ...

We've all been there before. Running along the basketball court or swimming across the pool, when, all of a sudden, we experience a sharp pain in our foot or leg. Muscle cramps are common, affect ...

slow-twitch muscle fibers, which move more slowly but help to keep you moving longer fast-twitch muscle fibers, which help you move faster, but for shorter periods “Twitch” refers to the contraction, ...

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 ...

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 ...