8 . For those who can stomach it, working out before breakfast may be more beneficial for health than eating first, according to a study of meal timing and physical activity.

Athletes and scientists have long known that meal timing affects performance. However, far less has been known about how meal timing and exercise might affect general health.

To find out, British scientists conducted a study. They first found 10 overweight and inactive but otherwise healthy young men, whose lifestyles are, for better and worse, representative of those of most of us. They tested the men’s fitness and resting metabolic (新陈代谢的) rates and took samples (样品) of their blood and fat tissue.

Then, on two separate morning visits to the scientists’ lab, each man walked for an hour at an average speed that, in theory, should allow his body to rely mainly on fat for fuel. Before one of these workouts, the man skipped breakfast, meaning that they exercised on a completely empty stomach after a long overnight fast (禁食). On the other occasion, they ate a rich morning meal about two hours before they started walking.

Just before and an hour after each workout, the scientists took additional samples of the men’s blood and fat tissue.

Then they compared the samples. There were considerable differences. Most obviously, the men displayed lower blood sugar levels at the start of their workouts when they had skipped breakfast than when they had eaten. As a result, they burned more fat during walks on an empty stomach than when they had eaten first. On the other hand, they burned slightly more calories (卡路里), on average, during the workout after breakfast than after fasting.

But it was the effects deep within the fat cells that may have been the most significant, the researchers found. Multiple genes behaved differently, depending on whether someone had eaten or not before walking. Many of these genes produce proteins ( 蛋白质) that can improve blood sugar regulation and insulin ( 胰岛素) levels throughout the body and so are associated with improved metabolic health. These genes were much more active when the men had fasted before exercise than when they had breakfasted.

The implication of these results is that to gain the greatest health benefits from exercise, it may be wise to skip eating first.

9 . Who is a genius? This question has greatly interested humankind for centuries.

Let's state clearly: Einstein was a genius. His face is almost the international symbol for genius. But we want to go beyond one man and explore the nature of genius itself. Why is it that some people are so much more intelligent or creative than the rest of us? And who are they?

In the sciences and arts, those praised as geniuses were most often white men, of European origin. Perhaps this is not a surprise. It's said that history is written by the victors, and those victors set the standards for admission to the genius club. When contributions were made by geniuses outside the club—women, or people of a different color or belief—they were unacknowledged and rejected by others.

A study recently published by Science found that as young as age six, girls are less likely than boys to say that members of their gender(性别)are “really, really smart.” Even worse, the study found that girls act on that belief: Around age six they start to avoid activities said to be for children who are “really, really smart.” Can our planet afford to have any great thinkers become discouraged and give up? It doesn't take a genius to know the answer: absolutely not.

Here's the good news. In a wired world with constant global communication, we're all positioned to see flashes of genius wherever they appear. And the more we look, the more we will see that social factors(因素)like gender, race, and class do not determine the appearance of genius. As a writer says, future geniuses come from those with “intelligence, creativity, perseverance(毅力), and simple good fortune, who are able to change the world.”

10 . We live in a town with three beaches. There are two parks less than 10 minutes' walk from home where neighbourhood children gather to play. However, what my children want to do after school is pick up a screen-any screen -and stare at it for hours. They are not alone. Today's children spend an average of four and a half hours a day looking at screens, split between watching television and using the Internet.

In the past few years, an increasing number of people and organisations have begun coming up with plans to counter this trend. A couple of years ago, film-maker David Bond realised that his children, then aged five and three, were attached to screens to the point where he was able to say "chocolate" into his three-year-old son's ear without getting a response. He realised that something needed to change, and, being a London media type, appointed himself "marketing director for Nature". He documented his journey as he set about treating nature as a brand to be marketed to young people. The result was Project Wild Thing, a film which charts the birth of the Wild Network a group of organisations with the common goal of getting children out into nature.

"Just five more minutes outdoors can make a difference," David Bond says. "There is a lot of really interesting evidence which seems to be suggesting that if children are inspired up to the age of seven, then being outdoors will be a habit for life." His own children have got into the habit of playing outside now: "We just send them out into the garden and tell them not to come back in for a while."

Summer is upon us. There is an amazing world out there, and it needs our children as much as they need it. Let us get them out and let them play.