Prepare yourself mentally by making a firm decision to exercise regularly. Everybody, even an instructor, has days when they don't feel like exercising.

Look for a group, or another person, who will make the same commitment to regular exercise. Knowing there is someone waiting for you can ensure you get out there for every exercise session.

Put aside at least 35 minutes to allow 20 minutes of exercise and time for preparation, recovery, and getting changed. This amount of exercise six times a week is enough to maintain basic aerobic fitness, control body fat, and increase mobility and strength in the major joints and muscles. Put in more time and you can work on improving flexibility, agility, endurance, strength, power, co-ordination and reflexes.

Measuring your fitness

Throw away your height and weight charts, and the scales in the bathroom. If you want a reliable measure of changes in body fat, try skinfold measurements, a direct measure of the amount of fat layered under your skin. This simple measure can be done at your local gym.

You can also measure your changes in body size by measuring the diameter of your neck, upper arms, chest, waist, hips and thighs (these are called girth measurements).

Planning your exercise programme

Sit down and write out your exercise programme. Ask yourself: 'Why do I want to exercise?' and 'What parts of my fitness need improving?'

Take a good look at your whole body in the mirror. You can change the look of your body by combining a reduction in body fat with an increase in lean body mass. Regular, low-level aerobic exercise will keep body fat levels down, and light endurance exercises will give greater muscle tone and definition.

If you get puffed after going up a set of stairs, put three aerobic sessions per week on your list. If you can't put your shoes on, you need a regular flexibility session. If you can't carry your groceries from the supermarket to the car, you need to increase your endurance.

Plan your list so that you are exercising six days a week, with one day off. Alternate an aerobic activity (such as walking, swimming or jogging) with one of your stretching or endurance sessions, or add in a relaxation session, such as yoga or tai chi, once a week.

Unhealthy exercise

The wrong kinds of exercise, or exercise done the wrong way, can actually be bad for your fitness and health.

• check with a registered fitness instructor for the latest information on safe and effective exercise
• don't exercise if you have a chill or fever, or if you have a cold
• don't overdo it - you will not be doing yourself any favours if you injure yourself
• use flexibility and stretching exercises to reduce the chance of injury
• if you have an existing medical problem, get approval from your doctor before starting a fitness programme.

Exercise equipment

All you need to start an easy exercise programme is a good pair of light exercise shoes. If you are going to attend an aerobics class, it makes good sense to spend a little more money and get a pair of leather aerobic shoes. These will outlast cheaper shoes, be more comfortable and may help prevent overuse injuries.

For gym or circuits, wear cotton clothing to absorb perspiration and prevent sweat pooling on equipment, and carry a small towel to wipe down the equipment after use.

Original material supplied by Monty Dortkamp, Chief Executive Officer, Fitness Australia, and Managing Director of the Australian Institute of Recreation. Edited by everybody, March 2005.