Introduction: Bone fracture as a result of diseases (osteoporosis, osteomalacia) or other causes, only in the country within a year cause 20% of deaths and 50% of people have serious disabilities or disorders. Given the importance of these fractures in increased mortality and reduced quality of life and to reduce the unwanted side effects of some medical interventions, evaluate the effectiveness of different treatment methods to reduce the risk of fracture is of great significance. Since the best type of exercise to stimulate and increase bone density and strength, weight-bearing exercise The aim of this study was to compare the effect of eight and 16 weeks of endurance training on bio mechanical parameters of the femur in male Wistar rats.
Methodology: 32 Rats with an age range of 50 to 60 days and an average weight of 160 ± 10 gr, were randomly divided into two groups: training (progressive running protocol for 8 and 16 weeks at a speed of 18-36 meters in minute for 20-60 minutes, five days a week) and two control group (no activity for 8 and 16 weeks). A day after the end of the training, the rats were sacrificed, the right femur bone were harvested, then By mechanical three-point bending test, the bio mechanical were measured. One way-ANOVA and Tukey post hoc test was used to compare bio mechanical parameters between groups (P>0.05).
Results: The results demonstrated a significant increase in biomechanical parameters (stiffness, high mechanical strength and maximum energy absorbed to the point of maximum strength) after eight weeks of training and a significant increase in femoral bone bio mechanical parameters (stiffness and maximum mechanical strength) after 16 weeks endurance training. In between training groups of eight and 16 weeks only in conjunction with variables, there was a significant difference maximum mechanical strength. Despite the differences between the means in relation to other variables, but the amount was not enough to make a difference is significant.
Discussion: Short-term and long-term endurance training, can be used as an effective, reliable and inexpensive in order to improve the biomechanical parameters and ultimately bone strength against fractures and diseases, to be used. Of course, with a doubling time seen the effects of endurance exercise on bone as much (twice) showed no increase (dependent response rate), but the biomechanical strength of the femoral bone healing were observed.