Knowing how many kilometers or miles per hour you’ll likely cover while hiking is of great importance. 【小题1】 It’s also important to build in time for breaks and extra time in case of bad weather or harder situations than expected.

If you’re not sure what your average hiking speed is, don’t worry. 【小题2】 Naismith’s rule is considered useful and was invented by the Scottish mountaineer William W. Naismith. It’s a great way to work out how long it will take you to complete your chosen path and it takes into consideration both distance and elevation (海拔高度).

It can be worked out as follows. One hour for every 3 miles plus an additional hour for every 600m of ascent (升高). So let’s say you wanted to know how long it would take to hike 6 miles with an elevation gain of 1,200m. That’s 2 hours for the distance and another 2 hours for the ascent, for a total of 4 hours. 【小题3】 It doesn’t include breaks.

【小题4】 You can choose exercises that you enjoy, whether that’s running, cycling, dance classes or something else. As long as it helps you build muscle (肌肉) strength, it will help you get your average hiking speed where you want it to be. Interestingly, specific weight training also helps increase your average walking speed on the path. It’s common knowledge that hikers should focus mainly on leg strength. 【小题5】

Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice.  

Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can lessen someone’s risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

We can’t ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it’s available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed. 

The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers’ muscle cells contained substantially more PGC-1alpha than at the study’s start. The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

Due to the heavy academic pressure and safety issues, our children’s movements are limited by a lack of extra-curricular activities, which usually ensure that they meet the daily recommended level of physical activity.

For those children attending a high school, my own included, the morning and afternoon walk could be the only chance that they get to spend time outside. This is a golden opportunity to add sports into their day, without taking part in group sports or going to a closed indoor gym(健身房).

For walking to school, there are also many other benefits, such as improving school performance, reducing anxiety, improving spirits, better sleep, a sense of independence,opportunities to meet friends or think alone, paying attention to small details and being amazed by the surrounding environment.

However, parents still have fears. Parents fear cars, injury, extreme weather and even wild animals. These fears, many of which are almost impossible to happen, prevent parents from allowing their children to do something that’s actually beneficial to them. “Removing an opportunity to be active leads to an increase in childhood obesity(肥胖), which can have a greater negative impact on a child’s life than the risk of being injured due to being active,” saidDr. Mariana Brussoni, a professor who researches children’s outdoor and risky play.

When it comes to changing the culture around parents driving children to school, much work still needs to be done. Therefore, parents should try to let go slowly and give up the idea that driving their children to school is convenient. Brussoni said, “We hope to shift parents from focusing on protecting their children to trusting their independent abilities.Schools can also play a role in encouraging children to walk to school.”