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.
physical activity; bone health; ergogenic aids
