1.人到老年时骨骼、关节都相应发生一定变化。表现为骨量减少,骨质疏松,引起骨密度和扩张强度下降,易出现骨折。体育锻炼是防止和治疗骨质疏松最有效的方法。参加运动可使骨外层密质增厚,而里层的松质在结构上也发生相应的变化以适应肌肉的拉力和压力的作用,使骨质更加坚固,可承担更大的负荷。运动还可改善骨骼的血液循环,增强骨骼的物质 1. People to the elderly when the bones, joints have undergone certain changes. The performance of osteopenia, osteoporosis, resulting in decreased bone mineral density and dilatation, prone to fracture. Physical exercise is the most effective way to prevent and treat osteoporosis. Participate in exercise can make the thickening of the outer layer of thick cortex, and the inner layer of loose structure in the corresponding changes also occur to adapt to the role of muscle tension and pressure, so that bone is more solid, can bear a greater load. Exercise can also improve the blood circulation of the bones, enhance the material of the bones