Body weight and shape are a consequence of lifestyle, and any change to them must involve a change in lifestyle. Exercise is an important component of the lifestyle balance that determines body weight, since energy taken in from food that is not expended as exercise is stored as fat.

Exercise is also important for reducing blood pressure and for boosting "good" HDL cholesterol: both of these changes improve cardiovascular risk.

The recommended level of exercise for best health is either

The form in which exercise is taken is important because it must be:

Strategies to consider are:

If you are keen to find out how you are going in a particular activity, you can determine the level of exercise you are doing by the effect it has on your pulse rate. Measure your resting pulse rate: it is commonly about 70/min. Calculate your maximum predicted heart rate as 220 minus (age in years): for a 50-year-old, it is 170/min.

Exercise at 50% of aerobic capacity will take the pulse rate 50% of the way from resting to maximum -- to 120/min for a 50-year-old with a resting pulse rate of 70/min. Exercise at 70% of aerobic capacity will take it to 140/min for that person.

You can determine your level of exercise by pausing to count your pulse rate, and doing the maths.