Effects of creatine and caffeine supplementation on the bone breaking force in rats subjected to vertical jumping exercise

Abstract

This study investigated whether supplementation with high doses of creatine and caffeine, alone or in combination, affects the bone breaking force of exercised rats. Rats were randomly divided into 8 groups: Sedentary or Exercised (placebo, creatine, caffeine or creatine plus caffeine). The supplemented groups received creatine (load: 0.430 g/kg body weight, for 7 days; and maintenance: 0.143 g/kg for 35 days), caffeine (10 mg/100g body weight, for 35 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training in water (4 sets of 10 jumps interspersed with 1 min resting intervals, 5 days/wk), for 6 weeks. Caffeine ingestion reduced the femur´s width, weight and breaking force, independently of exercise. Caffeine and creatine plus caffeine increased the urinary calcium excretion. Jumping exercise increased the bone breaking force independently of supplementation; nevertheless it did not change the weight and dimensions of the femur of the animals.