Gym

According to the National Health and Medical Research Council, a BMI of 20-25 is considered healthy for most adults. However, BMI can be an inaccurate measure of healthy weight for pregnant women, children, older people, athletes or very muscular people. It may also need to be adjusted for some ethnic groups, including people of Asian, Aboriginal or Torres Strait Islander descent.

Aerobic exercise makes your heart and lungs work harder, helping you build stamina. But this requires your heart to speed up so it's important to know how to get the most benefit from exercise without overworking this vital muscle. So what's a safe range for how fast your heart should beat while you exercise?

If you are concerned or are at increased risk of heart disease, see your doctor for advice before embarking on an exercise program.

Measure the circumference of your waist and hips in centimetres. Your waist circumference is measured at the narrowest point between your ribs and hips after exhaling. Once you have taken this measurement, insert it in the box on the left.

Your hip circumference is measured at the point where the buttocks are most extended when viewed from the side. Insert this measurement in the box on the right.

Waist and hip measurements and the advice below are appropriate for adults only and recommended ratios differ based on your age and gender. Enter your age and select the appropriate gender where indicated. Then click 'Calculate' for your waist-to-hip ratio and an explanation of how to interpret the result in terms of your health risk.