WALKING is one of the easiest and cheapest forms of exercise; it's a good de-stresser and good for general well-being.

But forget leisurely strolls through the countryside. For maximum benefit you should be out of breath, red in the face and sweating.

Hill walking should do the trick, or you could try power walking. This means perfecting your technique by putting your heel down before your toes, and moving your arms with your elbows kept in tight.

Try going faster for a short time until you feel quite breathless then drop the pace back down until you recover. Repeat this process throughout the workout.

Walking slowly for 60 minutes burns around 158 Kcalories. Walking fast for only 30 minutes burns around 127 Kcal.

WEIGHTS

Most of us trawl round the gym conscientiously doing our three sets of 20 reps on each type of resistance machine.

Although you can feel your muscles working, you find it easy to complete your 20 repetitions and you never have to give up half way through. But this won't tone muscle or change your body shape. For a muscle to increase in strength, it must be challenged beyond a level that it can comfortably work at, which means you have to use heavier weights.

When you first joined the gym, you may have felt a little strained. However, after a few weeks your body adapts then all you're achieving is maintenance.

The weights you are lifting need to be enough to cause the muscle to reach momentary failure - your body should give in at about the tenth repetition and you feel like you're not able to do any more even if winning the Lottery depended on it.

Research shows that if you train in this way you may need to do only one set of each exercise instead of the usual three, so you'll save loads of time. Increasing the weight you are lifting will also increase your metabolic rate. By gaining an extra 3lb in muscle tissue your body will burn 15 per cent more calories a day.

Women are often put off lifting heavy weights because they are anxious about becoming too big. But women's muscles don't pop up overnight. They become much more dense and firm before they increase in size.

If you feel you are beginning to get slightly more muscle than you need simply reduce the weight you are lifting and aim for slightly more reps - about 12 to 15.

SIT-UPS

Sit-ups, curl-ups or crunches won't make your stomach flatter.

The reason the stomach is not flat or firm in the first place is usually that a layer or two of fat has been deposited in this area. The only effective way to reduce fat through exercise is doing calorie burning aerobic activities such as running, cycling or swimming. To burn a pound of fat doing sit-ups would take 29 hours; to burn a pound of fat by running would take about five hours.

Working the muscle underneath the fat will not cause it to diminish. In fact it may cause muscle to build and the waistline to thicken.

Another problem with sit-ups is that they tend to work the stomach muscle which is responsible for allowing us to curl forward. This is not the muscle that makes the stomach flatter.

To work that muscle you simply need to pull your stomach in. We naturally work these muscles when we run or swim.

At the Bodysense health club, we are offering members a special 15-minute abdominal class three evenings a week, starting this month.

l New members who join Bodysense during January can save on the £125 joining fee. The health club is holding an open weekend on January 20-21 from 10am-4pm when visitors can tour the facilities.

Readers can also get free health and fitness advice from Mike Gallagher by e-mailing him at mgallagher5"Echo">Readers ca