4 . Running is often tiring and a lot of hard work, but nothing beats the feeling you get after finishing a long workout around the track.

But while it’s long been believed that endorphins (内啡肽) —chemicals in the body that cause happiness—are behind the so-called “runner’s high”, a study suggested that there may be more to this phenomenon than we previously knew.

According to a recent study published by a group of scientists from several German universities, a group of chemicals called endocannabinoids (内源性大麻素) may actually be responsible for this familiar great feeling.

To test this theory, the scientists turned to mice. Both mice and humans release high levels of endorphins and endocannabinoids after exercise. After exercising on running wheels, the mice seemed happy and relaxed and displayed no signs of anxiety. But after being given a drug to block their endorphins, the mice’s behavior didn’t seem to change. However, when their endocannabinoids were blocked with a different drug, their runners’ high symptoms seemed to fade.

“The long-held notion of endorphins being responsible for the runner’s high is false. Endorphins are effective pain relievers, but only when it comes to the pain in your body and muscles you feel after working out,” Patrick Lucas Austin wrote on science blog Lifchacker.

Similar studies are yet to be carried out on humans, but it’s already known that exercise is a highly effective way to get rid of stress or anxiety. The UK’s National Health Service even prescribes (开药 方) exercise to patients who are suffering from depression. “Being depressed can leave you feeling low in energy, which might put you off being more active. Regular exercise can improve your mood if you have depression, and its especially useful for people with mild to moderate (中等的) depression,” it wrote on its website.

It seems like nothing can beat that feeling we get after a good workout, even if we don’t fully understand where it comes from. At least if we’re feeling down, we know that all we have to do is to put on our running shoes.

5 . Exercise and I had never had a good relationship due to my fear of sports. From a young age, my dad _______ me into a dozen sports. I didn’t like any of them, _______.

When I entered the University of Regina, my dad _______ telling me “You have to find a way to stay _______.” or “You don’t want to get the Freshman 15, do you?” So I _______ to give swimming a shot, but I _______ managed to go to the pool twice during the fall semester (学期). Worse still, I was _______ to convince myself that’s OK.

The spring semester came. A friend of mine _______ me if I wanted to try Zumba (尊巴) with her. All I knew about Zumba was that it was basically a kind of exercise: dancing to Latin pop songs. It didn’t sound too bad, but I couldn’t be _______.

I went, and that was it. Zumba became my ________ of tea. The instructor would always say, “Don’t worry about the steps. Have fun. Do your own thing.” That removed my ________ of sports. I didn’t have to be ________. I didn’t even have to be good. I just needed to ________ the music and move. Zumba did ________ me from the Freshman 15, and it also did so much more. It let me make ________ with my unpleasant past about physical exercise, and enjoy staying healthy.

6 . Have you ever wondered how your favorite NBA team received its famous name? All NBA teams have an interesting story or a history behind their names. Some of the names reflected the city’s culture or history, others came from previous owners and many were selected through “Name the Team” contests.

For teams like the Los Angeles Lakers and the Utah Jazz, the names were not always a reflection of the city. Even though Los Angeles has no lakes, the Lakers name has been a city treasure for almost 40 years. Before going to Los Angeles, the team originated in Minneapolis, Minnesota. In1947, team officials changed the name to the Lakers to reflect the Minnesota State’s nickname, “Land of 10,000 Lakes”. The team name went unchanged after moving to Los Angeles in1960.

Because the Utah’s team originated in New Orleans, Louisiana, it was called the Jazz. In 1974, New Orleans club officials chose the name to represent the city for its reputation as the “Jazz Capital of the World”. The name stayed with the team even after they found a new home in Salt Lake City, Utah in 1979.

The original owner of the Chicago Bulls, Richard Klein, named the team the Bulls. He picked the name because a fighting bull is relentless and never quits. Klein, who founded the club in 1966, believed these qualities were necessary for a championship team and hoped his Chicago athletes would live up to the team name. The Bulls, the winner of the six NBA championships, has definitely followed the belief.

In 1967, the Indiana Pacers selected their team name in a different way from most other teams. Their decision was based on what they wanted to achieve in the NBA. Team officials chose the Pacers name because the organization wanted to set the “pace” in professional basketball.