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, ...

Many of us have felt a muscle in some part of our body suddenly and involuntarily tighten, causing a twitch or even severe cramp. Muscle spasms are common and typically don’t signal a severe health ...

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 ...

Whether you call it a charley horse, a muscle spasm or a cramp, sharp muscle pains can immobilize you for a few seconds or for even 15 minutes or more. There’s nothing worse than getting a leg cramp ...

Although creatine is a naturally-occurring compound in the body, more and more people are using powders to enhance their ...

Muscle cramps are sudden, involuntary contractions that can cause sharp, intense pain lasting from a few seconds to several minutes. They often strike during exercise, dehydration, or even while ...

Add Yahoo as a preferred source to see more of our stories on Google. How do you really want to age? Because to me, gracefully is beginning to sound a little... boring. This idea was first seeded by a ...

While people with medical conditions may require a heart-rate monitor during activity, most of us can use a simpler method to gauge intensity: a scale from 1 to 10 that measures how hard you feel your ...