2 . When it comes to being fit and healthy, we're often reminded to aim to walk 10,000 steps per day. This can be a frustrating target to achieve, especially when we're busy with work and other commitments.

The 10,000 steps a day target seems to have come about from a trade name pedometer sold in 1965 by Yamasa Clock in Japan. The device was called "Manpo-kei", which translates to "10,000 steps meter". This was a marketing tool for the device and has seemed to have stuck across the world as the daily step target. It's even included in daily activity targets by popular smart-watches, such as Fitbit.

In ancient Rome, distances were actually measured by counting steps. In fact, the word "mile" originated from the Latin phrase mila passum, which means about 2,000 steps. It's suggested the average person walks about 100 steps per minute，which would mean it would take a little under 20 minutes for the average person to walk a mile. So in order for someone to reach the 10,000-step goal, they would need to walk about five miles a day, nearly two hours of activity.

Researchers have investigated the 10,000 steps a day target. The fact that some studies have shown this step target improves heart health, mental health, and even lowers diabetes (糖尿病) risk, may, to some extent, explain why we have stuck with this number.

But while some research has shown health benefits at 10,000 steps, recent research from Harvard Medical School has shown that, on average, nearly 4,400 steps a day is enough to significantly lower the risk of death in women. This was when compared to only walking around 2,700 steps daily. The more steps people walked, the lower their risk of dying was, before leveling off at around 7,500 steps a day. No additional benefits were seen with more steps. Although it's uncertain whether similar results would be seen in men, it's one example of how moving a little bit more daily can improve health and lower risk of death.

3 . Sports can help you keep fit and get in touch with nature. However, whether you are on the mountains, in the waves, or on the grassland, you should be aware that your choice of sport might have great influence on the environment.

Some sports are resource-hungry. Golf, as you may know, eats up not only large areas of countryside, but also tons of water. Besides, all sorts of chemicals and huge amounts of energy are used to keep its courses(高尔夫球场) in good condition. This causes major environmental effects. For example, in the dry regions of Portugal and Spain, golf is often held responsible for serious water shortages in some local areas.

In fact, there are many environment friendly sports. Power walking is one of them that you could take up today. You don't need any special equipment except a pair of good shoes; and you don't have to worry about resources and your purse. Simple and free, power walking can also keep you fit. If you walk can regularly, it will be good for your heart and bones. Experts say that 20 minutes of power walking daily can make you feel less anxious, sleep well and control your weight better.

Whatever sport you take up, you can make it greener by using environment friendly equipment and buying products made from recycled materials. But the final goal should be "green gyms". They are better replacements(代替物) for traditional health clubs and modern sports centers. Members of green gyms play sports outdoors, in the countryside or other open spaces. There is no special requirement for you to start your membership. And best of all, it's free.