Muscle Cramps can be caused by many things, but the most pronounced during training and events are:
  1. Over Hydration is consuming too many ounces of fluid an hour that results in a flushing effect.
    Further Reading: The 10 Biggest Mistakes Endurance Athletes Make

  2. Electrolyte imbalances, which can be from too much sodium or not enough. Endurolytes provide the needed balance.
    Further Reading: Electrolyte Replenishment - Why It's So Important and How to Do It Right

  3. Calorie replacement from simple sugar sources - electrolytes are used to breakdown sugar instead of replacing critical nutrients needed for muscle expansion and contraction creating a demand for not only more fluid but more electrolytes to remain in balance.
    Further Reading: How should a person replace electrolytes and fluids during endurance efforts?