Caffeine may induce muscle twitching and cramps when you consume an excess amount of it. Other factors involved in muscle cramps include hot weather, loss of fluids or nutrients in the body and your body’s condition. You may experience muscle fatigue if you aren’t properly conditioned and the muscles cannot contract and tighten more effectively during exercise. Your muscle’s oxygen supply may deplete, leading to spasms. Your spinal cord reflexes are altered and continue to stimulate the muscle to keep contracting. Your caffeine intake may contribute to the cramping caused by these factors.
Involuntary muscle contracting in which the muscle does not relax leads to muscle cramps. The cramps may involve a part of the muscle, the entire muscle or several muscles in one area. Cramps commonly occur in the back of the lower leg or calf, back of the thigh from hamstrings or the front of the thigh. Cramps also affect the hands, arms, feet, abdomen and rib cage. Athletes experience muscle cramps from intense workouts. Older people have a susceptibility to muscle cramps because of muscle loss, which usually occurs in the mid-40s, according to the American Academy of Orthopaedic Surgeons.
An overdose of caffeine may cause muscle twitching, according to National Institutes of Health online medical encyclopedia Medline Plus. Muscle twitching occurs from minor muscle contractions or uncontrollable twitching in muscle groups controlled by a motor nerve fiber. Causes also include diet deficiency, side effects from medications or strenuous exercise. Muscle twitching can happen because of stress or anxiety or may signal an underlying disorder of the nervous system.
Heat and Dehydration
Caffeine may lead to excess urination, which can contribute to dehydration. Caffeine also increases body temperature. Dehydration and heat play a major role in causing muscle cramps. Working or exercising in intense heat can lead to dehydration and a depletion of salt and minerals because your sweat drains your body’s fluids. Research has had mixed results on the effects of caffeine, according to "Iron Man" magazine. Caffeine may cause a mild loss of water over a four-hour period, but some research shows exercising during the time can block water loss.
Excessive Caffeine Consumption
Many sports and energy drinks contain caffeine. The burst of energy it provides may help during exercise periods. Caffeine may also increase calcium in muscle for strong muscle contractions. However, excessive consumption of caffeine may cause muscle tremors as well as nervousness, restlessness, irritability, fast heartbeat and insomnia, MayoClinic.com points out. Excessive caffeine intake is the equivalent of drinking four or more cups of coffee a day. Many soft drinks, chocolate and medications also contain caffeine.