The correct answer is that you should do any moderate intensity activity that leaves you slightly out of breath, for at 30 minutes a day, at least five days a week. Being physically active at this level has been shown to greatly improve a person's health and wellbeing. The sort of activity you need to do is aerobic — which gives you heart and lungs a workout. You don't have to go to a gym — walking briskly part of the way to work, and taking the stairs instead of the lift all count towards this goal.

The correct answer is sprinting 100m. Exercise is anaerobic when there is not enough oxygen in the muscles. As a result, fats cannot be used for energy and glucose is not burnt completely, leaving behind a waste product called lactate. Sprint sports are anaerobic — and you'll probably know from experience that you can't keep them up for long.

The right answer is three out of ten people in the HK do enough physical activity to keep their heart healthy — although seven out of ten people think they are fit! But with small, gradual changes — walking more, putting more energy into household chores, it isn't too difficult to reach the recommended activity levels.

The answer is all of the above. All of these types of exercise will help to maintain strong bones. Walking may be the best specific exercise partly because it is the easiest for you to get going and maintain in the long term.

The correct answer is usually not true. Unless you have only a few pounds to lose it's quite hard to lose weight through exercise alone. Weight loss is all about burning more calories than you take in each day — and it is much easier to shave 500 calories a day by cutting back on fatty foods in your diet, than it is to exercise to that level. The average person would have to run about five miles to burn the same number of calories. However, regular exercise combined with calorie reduction gives you the best chance of losing weight and keeping it off.

The right answer is colon cancer. There is strong evidence that regular physical activity reduces the risk of colon cancer.

The right answer is false — regular physical activity can be helpful in controlling the pain of osteoarthritis. Contrary to what many people think regular activity can relieve joint pain and stiffness for people with osteoarthritis. For people with inflammatory type of the disease, rheumatoid arthritis, the picture is more complicated — it is best to rest for short periods on time during an arthritis flare-up. But for the rest of the time, staying active is an important way to keep muscles and joints healthy and supple.

The answer is starchy carbohydrate foods. Carbohydrates are the best fuel for exercise and so when you are exercising regularly it makes sense to ensure you include plenty of starchy carbohydrates into your diet, such as bread, potatoes and grains. The more you exercise, the more you will need, although for a moderate amount of activity you might not need to eat much more than usual.

The right answer is 50-70%. For moderate-intensity activity, your target heart rate should generally be 50-70% of your maximum heart rate. Your maximum rate depends on your age — you can get an estimate of maximum heart rate by subtracting your age from 220. For example, if you are 50 years old, the estimated maximum age-related heart rate would be calculated as 220 - 50 years = 170 beats per minute.

The right answer is false. Studies have shown that people can make striking health and fitness gains by taking up physical activity — whether you are nine or 90! Exercise can help you maintain bone strength, a healthy heart and help to prevent the onset of diabetes. It isn't necessary to exercise strenuously to improve health and vitality, and it is fine to begin exercising for just 10 minutes a day and build up gradually.