Why choose free weights and racks? Dumbbells are not just for bodybuilders and weightlifters. Strength training is one of the key elements of a well-rounded fitness programme, and everyone can feel the benefits of it, whatever their level of fitness.

Not only does greater upper body strength help you in daily life and improve your appearance, but increasing your muscle mass is also another way to burn more calories. Every additional pound of muscle you carry burns 20 - 40 calories per hour.

The chrome-plated free weights and racks you may have seen in the gym may look formidably expensive, but these are at the top end of the range of dumbbells available. The least expensive versions are made out of plastic and filled with sand. Their main disadvantage is their bulkiness, but in other respects they can work just as well as a more expensive set.

Here are three things to think about when deciding which dumbbells to buy:

Price

Individual dumbbells start at only a few pounds in price, although a full set on their own stand will take you into three figures. However, when you consider that you might pay the same for two or three months' gym membership, a set of dumbbells is a relative bargain.

Weight

Choose a set with enough variety of sizes to enable you to use them for a full range of exercises. Squats, for example, require heavier dumbbells than one-arm curls or lifts.

Convenience

Choose your dumbbell set based on where you plan to store them, and how much space you have available in your home. Buying a set with its own tree could make storage more efficient.