Make the marinade: Add soy sauce, oil, sprite, garlic powder and horseradish to a large ziplock bag. Add chicken and marinate for 1-3 hours.

Grill the Chicken: Heat grill to medium. Spray with cooking spray or rub the grill grates lightly with oil. Lay chicken on the grill and cook for 3-4 minutes on each side, flipping only once, until cooked through. (I don't typically use a thermometer, but if you do, the chicken should be 165 degrees F at its thickest part).

Move to a plate to rest for a few minutes before serving.