If you think of your body as an engine your metabolic rate is the rate at which your engine burns fuel. When you are sitting or lying or on the couch your engine is idling at a resting metabolism rate (RMR) - just quietly keeping your body alive building and breaking down cells, digesting food, breathing air and pumping blood. When you exercise you are revved up to a faster Exercising Metabolism Rate (EMR). An unfit couch potatoe body is like a badly tuned motor car - operating well below its potential.

The factors that alter your resting metabolism are:

• The amount of muscle tissue in your body - the more muscle the higher you resting metabolism.
• Your age - the older you are the slower your resting metabolism. The slowing down is caused by loss of muscle tissue. If you don’t exercise you lose about 220g of muscle tissue a year after the age of 25 - a scary 40% of your muscle by the time you hit 70. The good news is you can stop this wasting process if you exercise and keep building muscle.
• Gender. Males have a higher resting metabolism.
• Genetics. Polynesians normally have a lower resting metabolism.
• Physical Activity - Regular exercise at a moderate to high intensity as well as muscle toning promote a higher resting metabolism.
• Pregnancy causes your resting metabolism to rise.
• Crash dieting reduces you resting metabolism.

Beware of any pills potions that promise to increase your metabolic rate. Many NZ women have experienced the unhappy side effects of these pills, which can cause sleeplessness and erratic behaviour and addiction - and the withdrawal symptoms are dreadful. Spicy foods don’t do the trick either despite what you may have heard, spicy foods are not a metabolism booster they just make you sweat.

The good news is that exercise benefits your metabolic rate not only when you are exercising but afterwards as well. It can take up to 18 hours after a workout for your metabolic rate to drop back to a normal level.

In summary - A lean muscular body is an efficient energy-burning machine, even at rest. Your muscles do a lot of the calorie burning work for you. That is why people who are toned and trim find it relatively easy to maintain their weight whilst fat people find it an uphill battle no to put on even more fat.