Weight bearing exercise benefits bones
1st September 2009
By Deborah Condon
Weight bearing exercise during adolescence, such as fast walking, running and dancing, appears to be the best type of exercise for maintaining bone strength later in life, the results of a new study indicate.
Japanese researchers looked at women aged 52-73 who had already gone through the menopause. They were grouped according to what type of sporting activities they had done during their physically formative adolescent years, i.e. 12-18.
Some of the participants had been involved in high impact weight bearing activities, such as athletics, tennis and volleyball while they were teenagers. The rest had either participated in low impact weight bearing exercise, such as swimming, or had done no exercise at all.
The researchers assessed indicators of bone structure (mineral density and content) in the spine and thigh bone (femur), and the size and geometry of the femur were also measured. The size, shape, and structure of the bones all reflect bone strength and how well the skeleton compensates for the bone loss that naturally occurs after the menopause.
The study found that there was no difference in bone mineral density between the two groups, but those who had participated in weight bearing sports between the ages of 12 and 18 had significantly greater bone mineral content in both the spine and the thigh bone than those who had not.
The outer femoral bone was also larger among those who had undertaken weight bearing exercise. This ensures greater resistance to fracture during pressure from movements, such as bending.
The researchers noted that none of those with the strongest bones were doing any weight bearing exercise at the time of the study, suggesting that the benefits of this type of exercise during adolescence last for over 40 years.
Details of these findings are published in the British Journal of Sports Medicine.