3 . Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50-kilometer race walk, which is about five miles longer than the marathon. But the sport’s rules require that a race walker’s knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It’s this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

Like running, race walking is physically demanding, she says, According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories(卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.

However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

As a result, she says, some of the injuries associated with running, such as runner’s knee, are uncommon among race walkers. But the sport’s strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.

6 . People refer to never forgetting how to ride a bike or throw a baseball as examples of “muscle memory”, the result of a motor learning.     1     It is a phenomenon that previously trained muscles acquire strength after a period of disuse.

Previous research has shown that the changes actually persist in the muscles themselves. In one study of mice, the results suggest that after nuclei in muscle cells multiply in response to an overload of training, those extra nuclei aren’t lost during subsequent periods of inactivity. They are retained (保留), essentially waiting to be reactivated. If you fell off the fitness wagon (马车) during the pandemic, don’t be frustrated. Once you have got additional nuclei, you are banking the capacity.     2     In fact, a recent study revealed that less than eight weeks of retraining were needed to regain your former fitness. It depends on how fit you were initially, how long the layoff was, how old you are and how long you’d been exercising.

    3     It means you still have a distinct advantage when it comes to regaining your former level of fitness. And the principle applies to both resistance training and endurance training. The best way to regain your muscle memory is to start at a level below what you were accustomed to doing, and then gradually increase in terms of duration, frequency, then intensity.     4    

Ultimately, muscle memory is a payoff for all the past work you put into learning a sport.     5     You will never know how much muscle memory you may have until you start training again.

9 . The Upside to Being Outside

Research shows that being in nature makes people feel good, whether they’re roughing it in the wilderness for days or just hanging out at a local park for a while. One study was conducted in the city of Birmingham, Alabama. Researchers found that most participants’ mood and well-being improved significantly when they spent time in urban parks, even though the average visit was only around half an hour.

    1     For example, scientists in the United Kingdom studied the impact of the “30 Days Wild” campaign. It challenged people to interact with nature for 30 days by enjoying earthy activities like feeding birds and planting flowers. Participants were measurably happier and healthier throughout the challenge…and for months afterwards, too.    2    

How does nature boost people’s happiness? Scientists say that spending time in natural settings reduces stress and anxiety, which benefits mental and physical health. Research shows our brains are more relaxed in natural settings.

To most people, it’s not news that nature can be calming. But multiple studies have found that spending time in nature also has some more surprising benefits, like improving creativity and problem-solving.     3     Another found that exposure to nature helped people score better on tests. That’s more proof that going outside is a smart move!

What accounts for the connection with cognition and creativity? It could be that a good dose of nature acts as a cure to information overload. Everyday life involves a lot of multitasking. Some scientists theorize that spending time in nature enables our brains to rest and recover from mental tiredness.     4    

Naturally, scientific studies don’t cover everything that’s great about the great outdoors.     5     From recreation and exercise to happiness and creativity, there are lots of upsides to getting outside.