Muscle fatigue, dehydration, electrolyte deficiency or a combination of these three could lead to cramping in your hamstrings. Initial treatment includes rest, ice and light stretches, and strength exercises and adequate water intake help prevent future cramps. Consult a physician about reoccurring or prolonged hamstring cramps.

Why It Happens

Running can cause your hamstrings to fatigue and therefore cramp or spasm. Dehydration from excessive sweating and lack of water intake also causes muscle and hamstring cramps. Muscle cramps may be a symptom of mineral and electrolyte imbalances such as low calcium, sodium and potassium as well. With dehydration and mineral and electrolyte imbalances, muscle cramps may start with one muscle group like your hamstrings, but will continue to spread to other muscles. Muscle fatigue, on the other hand, will only cause cramping within the affected muscle or muscles such as your hamstrings.

Other Factors

Poor conditioning, tight and weak hamstrings, and muscle strength imbalances between your hamstrings and quadriceps increase your risk of hamstring cramps. Additional training risk factors include increasing your pace or distance too quickly and overtraining. Hot weather, inadequate water intake during the day, alcohol consumption and poor diet further contribute to dehydration and electrolyte and mineral imbalances.

Stretch It Out

When suffering from a hamstring cramp, immediately stop running and lightly stretch your hamstring after the cramp has stopped. The standing hamstring stretch is performed with your feet shoulder width apart. Slowly bend at your waist until you feel a light pull on your hamstrings. Hold for 30 seconds and repeat up to three times or until cramping subsides. Ice and a gentle massage may also alleviate cramping and reduce soreness. To rehydrate and replenish mineral and electrolyte levels, consume sports drinks, bananas and other supplements. Some people think drinking pickle juice will reduce and prevent exercise-induced muscle cramps by increasing your electrolyte levels. However, a 2009 Brigham Young University study found that consumption of pickle juice did not significantly influence electrolyte levels. Consequently, drinking pickle juice is not a sufficient treatment for hamstring cramps.

Taking Care

Drinking at least eight glasses of water daily and eating a well-rounded diet including fruits and vegetables can reduce your risk of dehydration and mineral and electrolyte deficiencies. Warm up prior to running and stretch afterward to keep your hamstrings loose. Gradually progress your runs to prevent muscle fatigue and over-training. Regular strength exercises targeting your hamstrings, such as bridges, deadlifts and knee curls, can further reduce your risk of cramping. Check with your doctor if cramping continues to rule out any undiagnosed medical conditions.