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Why measure steps? |
Dr Andrew Binns, How inactive are we?
It may come as no surprise that we are far less physically active than our parents or grandparents, but just how much more sedentary we are may come as a surprise. If you really think about it though, you will realise how much automation and sedentary behaviour has crept into our lives in the last century. Time spent in front of television and computers and many of life's other conveniences have gradually replaced opportunities to be active. This has been the main contributor to our putting on an average of one gram of weight a day.
How physically active do we think we are?
This is actually quite a problem. There is increasing evidence that we overestimate how much exercise we take, just as we underestimate how much food we eat. These false impressions are even more marked with obese people. To keep us honest with ourselves we need to find ways of making sure we know just how inactive we are so that we can take some action to do something about it. Pedometers that measure steps are simple electronic devices that strap on to a belt to measure just how physically active we are.
What's the best fat burning activity?
One of the most energetic things the body can do is carry its own weight. Just standing up is an energetic process. Walking is even better. And walking quickly burns a little more fat than walking slowly. Activities like swimming and cycling are good but not nearly as good as walking because the body's weight is supported by the water or the wheels in those activities. Walking at a moderate pace is actually all that is necessary for managing weight and for good health.
How many steps should I be taking each day?
To lose fat and for health maintenance carrying your body weight over a distance is the way to go. For a person weighing 80kgm about 30 standard walking steps will burn about one kcal of energy. Given that a daily rate of around 250 kcals is recommended as the minimum for good health and weight maintenance, this sets the minimum number of steps required at around 7,500.
The good news is that the bigger you are the more energy it takes to move that weight and hence fewer steps are needed. If the steps are longer and faster, such as when jogging or briskly walking there is also less needed.
Motivation
Becoming motivated and staying that way is the biggest challenge for weight control and health. Going for walks with friends or the dog is helpful. For self motivation think of the pedometer which is an inexpensive gadget to feedback to ourselves just how active we are compared with how active we should be. Not enough on one day can be compensated for by more the next. It is actually fun keeping an eye on the number of steps we do in a day. One soon learns creative ways to increase the number by accumulating more throughout the day. This is the aim of the game.
The evolution of physical activity
Many studies show a marked decline in calorie intake over the last few decades. However, we have seen a dramatic increase in the number of our population who are overweight or obese - about half of women and two thirds of men in Australia. Obviously how active we are is an important component to energy imbalance. We can look at this in evolutionary terms.
Man 1
The hunter gatherer needed to be very active to survive. He may have taken 25,000 steps or more a day to hunt enough food for himself and his family. From an evolutionary viewpoint he survived because he was able to store fat efficiently, which enabled him to survive famine. Most of his calories were provided as carbohydrate rather than protein and with very little fat. Obesity was unlikely to exist and BMIs (body mass index) in the range 16-20 would have been usual.
Man 2
Industrial man was reasonably active and moving around all day. He may have accumulated 15,000 steps a day or more but his diet contained a lot more fat, particularly saturated fat. His intake of carbohydrate and protein was correspondingly lower. His BMI may well have been in the 20-25 range and rarely one of his workmates may have become overweight or obese.
Man 3
Postmodern man may well drive to work, take the lift to his desk where he spends the day and then go home to eat, watch television and go to bed. He may only walk about 3,000 steps a day and may have a diet high in fat and low in carbohydrates. His BMI has a high chance of being in the obese range above 30. He also has a high chance of developing the metabolic complications of obesity. In order for him to adapt to his new environment and avoid energy surplus he must change his diet to one that is lower in fat - 30-40 grams per day - and become more active.
Increasing our steps
The table has been worked out as to how many steps a day we need to maintain weight and health. In order to calculate how many steps we take, a useful tool that uses the modern technology that contributed to the problem to help solve it, is a stepometer. This is a simple step counter.
Stepometers are cheap and an excellent motivating tool to get people moving around a bit more. They are reasonably priced at about $25. Getting ourselves moving again and increasing our daily number of steps to at least 7,500 is a major challenge. However the rewards are there for our health as so many medical problems relate to being overweight or obese.
How many steps do you take a day?
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