MEN V WOMEN
How bones differ between the sexes
Throughout childhood and early adulthood the pattern of bone growth is similar in males and females but thereafter it starts to differ, says exercise medicine consultant Dr Cathy SpencerSmith. ‘Much of the quality of bone is dictated by levels of sex hormones (oestrogen and progesterone in women and testosterone in men),’ she says. ‘The higher the levels, the healthier the bone. Men typically have higher bone-mineral density (BMD) than women, something that becomes an advantage in later years, as BMD can start to drop off by one to two per cent per year after the age of 50.’ This decline is increased for a time too as women go through the menopause and their production of sex hormones decreases sharply. And the diet culture, which Spencer-smith says is more prevalent among women than men, means more periods of time where calorie intake is decreased, which can further lower bone mineral density. However, diets have more impact on male BMD than female. ‘Men are now falling into the trap of under-consuming calories,’ says Spencer-smith, ‘and with higher average body weights the forces felt by men’s skeletons are higher, amplifying any problems with training. Men with a body mass index of 25 and above are particularly at risk of bonerelated injuries.’ Department of Health guidelines for healthy daily calorie consumption are 2,500 for men and 2,000 for women, though your needs will be higher when training.