Metabolism and your age

In your forties
During your forties your bmr and digestive system start to slow down. Hormone fluctuation can arise at this time, particularly in the mid to late forties with the onset of menopause; again, bone density can be improved with regular toning exercises helping to prevent osteoporosis.

In addition, thyroid problems are more likely to arise during this decade. The thyroid gland in the neck helps to regulate the bmr. When it is not functioning properly, weight, energy levels, muscle strength, skin, hair and periods are affected. Too much thyroxine (the hormone produced by the thyroid) in the body can cause thyrotoxicosis, doubling the bmr. Too little thyroxine results in myxoedema, when the bmr may drop to 30-40 per cent below its normal rate. Because exercise speeds up the metabolic rate, it's helpful for those with an underactive thyroid.

In your fifties
The average age for the onset of menopause is 51. During the menopause the body produces less oestrogen, which can cause the rapid loss of bone density. For some women, the hormonal changes can trigger weight gain. Given that the metabolic rate continues to slow with age unless it's speeded up by regular exercise, menopause weight gain can be difficult to lose.

In your sixties and beyond
During the sixties, weight generally returns to normal. This is also a time when cholesterol levels need monitoring to protect the health of your heart. There are three types of cholesterol, or fats in the body: LDL (low-density lipoprotein), HDL (high-density lipoprotein) and VLDL (very low-density lipoprotein).

The ratio between them indicates in the artery walls, increasing the risk of heart disease and stroke. Aerobic exercise helps to decrease LDL cholesterol and raise HDL, as can eating fewer saturated fats.

Extract from The No-gym Workout, by Lucy Wyndham Read