1 . More scientists are researching cellular senescence (细胞衰老) — a state in which cells no longer divide. Senescent cells, which buildup in older bodies, have something to do with age-related conditions such as dementia (痴呆) disease.

Scientists are researching drugs that treat senescent cells. But the most promising tool against the bad influences of senescent cells, experts say, is exercise.

Today, LeBrasseur, who directs a center on aging at Mayo, says exercise is “the most promising tool that we have” for good health in late life, and that its power spreads to our cells. Research suggests exercise prevents the build-up of senescent cells, helping the immune system (免疫系统) clear them and fight the cell damage that can affect (影响) aging.

Last year, LeBrasseur led a study that provided the first sign in humans that exercise greatly affected senescence. It cut signs in the bloodstream of the influences of senescent cells in the body. After a 12-week exercise program, researchers found that older adults had cut signs of senescence and improved body strength, physical ability and reported health. A recent study collect seven more facts — in animals and humans — for exercise as a treatment to fight against senescence cells.

While such studies are not well-known outside scientific circles, many older adults connect exercise with youthfulness. Farmer Mike Gale, 81, put in a track and field throwing circle on his large farm in California. He and some of his friends throw the discus and use other exercise equipment. “I’d like to be competing in my 90s,” Gale says. “Why not?” 95-year-old Richard Soller says exercise keeps him fit enough to deal with what comes his way — including the discovery that his wife of 62 years had developed dementia. The two sometimes walk the streets of their neighborhood together, holding hands. “Do as much as you can,” he says. “That should be the goal for anyone to stay healthy.”

2 . For some school children, PE is the best lesson of the week — a chance to leave the desk behind, get outside, and enjoy a run around with friends. For others, it is often an unhappy experience — a time when they feel embarrassed, and may even experience physical pain.

The idea of competitive sport was a clear source of argument. Those who were good at it did not want those less able to “get in the way”, while those less skilled felt annoyed for being made to compete. They also felt less “liked” by their PE teachers and their more sporty classmates.

Research shows that participation (参与) first over excellence can dramatically increase the confidence and participation rates of those less skilled — because it really is the taking part that matters. If schools value taking part above winning against other schools, the nature of PE changes.

As one pupil commented (评论): “I have actually joined the football team now, because all the violence has gone. Before it was, ‘You made us lose the game…, it’s all your fault.’ With the new approach, it is more like we are all in there just trying to get better. No one is to blame. Now it is worth doing.”

To those who argue we need competitive sport to “build character”, I would point out that there is quite simply no evidence to support this view. But what we can build if we allow young people to work together in a spirit of support and cooperation in the competitive sport is leadership and mutual understanding.

If we need competitive sport to build our national teams, this should happen out of school. PE is about the participation of all — not the excellence of a few.

At home, the most important thing a parent can do for a child who struggles with PE is to take their concerns seriously. Being physically active is very important for children and young people, so how, when, and at what level they do it should be their first choice.

Here’s one more reason to get up and exercise! A newly     1     (publish) study in JAMA Neurology has found that walking about 10,000 steps per day     2     (help) lower the risk of developing dementia (痴呆症). In fact, 4,000 steps a day is enough     3     (decrease) dementia risk by one-quarter, according to the study.

Furthermore, people who walk with “purpose”—     4     a pace of over 40 steps a minute —     5     (be) able to cut their risk of dementia by 57 percent with just about 6,000 steps a day. “It is a brisk (轻快的) walking activity, like a power walk,” study co-author Borja del Pozo Cruz told CNN.

Even people     6     walk about 3,800 steps a day at any speed can cut their risk of dementia by 25 percent, the study found. Such a number of steps would be enough for     7     (beginner), especially those who usually sit for a long time each day.

“There is evidence     8     physical activity can enhance (提高) dementia     9     (prevent) among the general population,” Del Pozo Cruz said. “We thought that by providing specific stepping recommendations, people would pay more attention to physical activity, as steps and walking are something everyone understands     10     require very little resources.”

Walking, if you do it vigorously enough, is the overall best exercise for regular physical activity. It requires no equipment, everyone knows how to do it and it carries the     1     risk of injury. The human body is designed to walk. You can walk in parks or along a river or in your neighborhood. To get     2     benefit from walking, aim for 45 minutes a day, an average of five days a week.

Strength training is another important     3     of physical activity. Its purpose is to build and     4     bone and muscle mass, both of which shrink with age. In general, you will want to do strength training two or three days a week,     5     recovery days between sessions.

Finally, flexibility and balance training are     6     important as the body ages. Aches and pains are high on the list of complaints in old age. The result of constant muscle tension and stiffness of joints is     7     and simple flexibility training can     8     these by making muscles stronger and keeping joints lubricated. Some of this you can do whenever you stretch. If you watch dogs and cats, you’ll get an idea of how natural it is. The general     9     is simple: whenever the body has been in one position for a while, it is good to     10     stretch it in an opposite position.

Three years ago, Nick was     1    (terrify) of walking or skating on ice.     2    (Lucky), he met a great teacher, with his teacher’s help, not only did Nick learn how to skate     3     also he was persuaded     4    (try) ice hockey. Nick now is training for national     5    (competition) and hopes to be a champion one day.

Nick says, “Sports and games build our bodies, prevent us from     6    (get) too fat, and keep us     7    (health). They also give us     8     (value) practice in helping the eyes, brain and muscles to work together. Sports and games are also very useful for character-training.”

Of course,     9     state of physical and mental health allows you to take part in exercise comfortably and     10    (enjoyable).