Muscle cramps can be excruciating and debilitating, often strike without warning. If you find your back tensing up and cramping after you stretch, it may be related to any number of underlying causes from dehydration to an insufficient supply of blood leading to muscle tissues.
Muscle cramps that occur in your back after stretching may indicate overexertion, inadequate physical conditioning, or may simply mean that you have not been stretching enough. According to the American Academy of Orthopaedic Surgeons, regular stretching ensures that muscle fibers contract more dynamically during physical activity. Lack of stretching can lead to muscle fatigue, which changes the spine's neural reflex response and causes the cramping muscles to keep contracting rather than relax.
Cramping back muscles after stretching can also point to insufficient hydration during exercise. Adequate water intake is crucial during exercise. Without enough water the body's self cooling mechanism becomes compromised, leading to muscle fatigue, loss of coordination, loss of energy and intense muscle cramps, according to the American Council on Exercise. Make sure you hydrate yourself before, during and after exercise.
Sweating causes the body to lose essential minerals such as potassium, sodium, calcium and magnesium known as electrolytes. Electrolytes maintain the chemical composition of blood and oversee muscle action also, according to the U.S. National Library of Medicine. Mineral loss may occur as a result of certain diuretic medications or kidney problems and can lead to muscle cramps and spasms. Speak with your doctor if you take medications regularly to find out if they may be affecting your body's mineral balance.
Muscle cramps sometimes indicate underlying medical issues such as thyroid or hormone disorders, diabetes, hypoglycemia and nerve problems. Speak to your doctor or health care practitioner if the muscle cramps in your back begin to happen regularly, do not respond to increased hydration or improved conditioning, or if they begin to occur outside of exercise.