World Hungers for Sand while Germany has much of it

This stock photo shows a beach in Monterey, California. (AP)
This stock photo shows a beach in Monterey, California. (AP)
TT

World Hungers for Sand while Germany has much of it

This stock photo shows a beach in Monterey, California. (AP)
This stock photo shows a beach in Monterey, California. (AP)

As incredible as it sounds, the world is running out of sand. Or at least the kind of sand that industries need.

According to the UN Environment Program (UNEP), sand and gravel, known as aggregates, are used in volumes greater than any other raw material on earth except water. And their use greatly exceeds natural renewal rates, the program says.

Kay-Christian Emeis, director of the Institute of Coastal Research at the Helmholtz Center for Materials and Coastal Research (HZG) near Hamburg, Germany, says that worldwide demand for sand is enormous, an estimated 14 billion tons annually, more than half of which is used in Asia.

UNEP explained that sand is indispensable in the industry of many things, such as glass, paper, toothpaste, detergents, cosmetics, electronics and aeronautics, and it is used predominantly in construction and land restorations. Concrete is made with cement, water, sand and gravel.

Even desert countries, like Saudi Arabia and the United Arab Emirates, import sand (marine sand) from Australia, for example to build their skyscrapers.

Harald Elsner, a geologist at Germany's Federal Institute for Geosciences and Natural Resources (BGR) notes that the mineral composition and grain-size distribution of desert sand are not suited to construction.

Most desert sand cannot be used for concrete or land reclamation, as wind erosion shapes round grains that do not blend well, UNEP added.

When Dubai created a group of 300 artificial islands representing a map of the world, it used 450 million tons of Australian sand. As the HZG explains, desert sand would be blown away much too quickly.

The worldwide construction boom, particularly in China, has not left Germany a bystander. According to government statistics, more than 270,000 dwellings in Germany were either newly built or reconstructed in 2016, which is a high record.

This year, the German Construction Industry Federation expects the number to top 300,000.



Should You Stretch before Exercise? After? Never? Here’s What to Know

 Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
TT

Should You Stretch before Exercise? After? Never? Here’s What to Know

 Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)

For many people of a certain age, high school gym class began with reaching for their toes. Then, over the years, we were told it was better to stretch after exercise.

It turns out, both those things can be true, but the differing advice has created some confusion.

Stretching can help make you more flexible, improve range of motion in your joints — and feel good. David Behm, who researches human kinetics at Memorial University of Newfoundland in St. John’s, Canada, offers this advice on when to stretch and how to do it safely:

Warm up first

It’s almost always good to stretch, but it’s better if you warm up first, said Behm, author of "The Science and Physiology of Flexibility and Stretching." He recommends a light aerobic activity such as jogging, walking or cycling for five or 10 minutes.

Follow that with some static stretching, the traditional way of reaching and holding a position (think back to that gym class). You can then do activity-specific dynamic stretching, in which you warm up the muscles with repetitive movements like leg lifts.

Behm says one minute is "the magic number" for how long to do static stretching per muscle group without fatigue.

Expand your definition of 'stretching'

Should you always stretch before exercising? If it's traditional stretching, not necessarily.

The better question, Behm says, is, "Should people increase their range of motion? Should people have better flexibility? And that is yes, because it helps prevent injuries. It helps with health. But you don’t have to stretch to achieve that."

Resistance training, for instance, can be an effective form of stretching, he said. Doing a chest press increases range of motion in your deltoids and pecs, whether with barbells, dumbbells or machines, so there is no need to stretch beforehand. Just make sure to start with a small amount of weight to warm up and then add more to train.

"You probably don’t have to do extra stretching unless you’re a gymnast, a figure skater, or even a golfer who needs a great range of motion through that swing," Behm said.

Nor do you need to stretch first if you’re going for a leisurely run. Simply start with a slow jog to warm up and then increase the pace.

Don't do it if it hurts

After exercise, "light stretching is OK, as long as you don't reach a point where you're feeling pain," Behm said. Since your muscles will be warm by that point, overdoing it makes you more likely to injure yourself.

Foam rollers can help with muscle recovery and have been shown to increase range of motion as well as stretching.

Do some static stretching before sports

If you’re playing a sport, Behm said, static stretching beforehand helps reduce muscle and tendon injury.

"If you’re going to do an explosive movement, change of direction, agility, sprint, any of these explosive activities that involve your muscles and tendons," he said, "you’re going to be stronger if you do static stretching."

People can especially get in trouble when they go back to a sport they used to play, whether it's tennis, surfing or any sort of team activity.

Also, stretch both sides equally. Lacking flexibility on one side also can lead to injury.

Sounds simple. Why all the confusion? Different studies over the years have either encouraged or discouraged stretching before exercise. Behm says that partly because some studies didn't reflect real-life conditions, or were designed with elite athletes in mind, not regular people.

"If you’re Usain Bolt, it makes a difference," said Behm. Not so much for the rest of us.