Thanks to the internet it is now quite easy to work out how many calories you have burned during a particular exercise session. There are a number of websites that have created their own online calculators. Just enter the activity, your weight and the duration of your work-out, and the calculator will tell you the number of calories you shed.

For example, a 180-pounds man who engages in an hour of backpacking will burn 486 calories, according to one online calculator. By contrast, an hour spent walking the dog will burn just 356 calories, an hour of energetic dancing (really kicking up your heels, according to the website) will burn 410 calories and an hour of tennis will burn 658 calories.

One problem, of course, is that different websites use differing methods of calculation. Thus, a second website says that an hour of backpacking for a 180-pounds man will burn 571 calories, while an hour spent walking the dog will burn an amazing 815 calories. Clearly there are marked differences between just these two websites, let alone between the many others that are out there.

If you are serious about monitoring your calorie burn rate, then you would be advised to buy your own calorie calculator. There are a growing number of these on the market, some with quite sophisticated functions. In fact, some heart rate monitors now come with a calorie burn function, so you can do far more than just check your calories.

But a word of caution - success in burning calories does not mean that you are automatically leading a healthy life. A balanced diet low in fat is also important, along with sufficient rest and a healthy attitude to life.