It's a question with an answer that researchers are still trying to better understand: how much exercise do children need daily?  In the United States, the Center for Disease Control and Prevention recommends that children and adolescents receive at least one hour of physical activity daily. The British health service recommends the same.
There are also questions about the types of physical activity that children and adolescents should do, how to get young people excited about exercise, and what research efforts are being made to better understand fitness at the molecular level
How the kids should exercise
At least three days of a children's week should include muscle strengthening exercises such as gymnastics, climbing or playing on jungle gyms, as well as bone strengthening exercises such as jumping, jumping or running, according to CDC and NHS.
"One of the key reasons why children should be active is their bone health, because it turns out that in adolescent years, 33% to 43% of total bone mass is acquired," said Craig Williams, a professor of pediatric physiology Head of the Child Health and Movement Research Center at the University of Exeter in England.  "The highest bone mass is reached in the third decade of life. … After that, it diminishes due to aging, but if we can increase our peak bone mass in childhood and adolescence, studies have shown that there is a 10% increase in bone mineral density The development of osteoporosis is delayed by 13 years ", said Williams
" The most important message is that children and adolescents have to be physically active every day and have to adopt this habit into adulthood. "
Meanwhile, aerobic activity should account for the majority of your child's 60 or more minutes Exercise one day – from moderate activities such as brisk walking to vigorous activities such as running – and, according to the CDC, intensive aerobic activity should be performed at least three days a week ,
If your child suffers from a chronic illness or disability, The CDC also suggests talking to a health care provider to determine the best physical activity routine. In addition, the best way to encourage more physical activity in your child's daily life may depend on age and interests.
Make fun – and off the couch – fun for young children
"For younger kids, having them outside friends can be a cheap way to promote the game, especially when they're out of sedentary activities like computer games holds, "said Williams.
"Overall, activity will become more and more a habitual image and part of daily life will become the norm.The value, of course, is that strong evidence shows that in children and adolescents a higher level of physical activity is associated with multiple positive health outcomes, including cardiorespiratory and muscular fitness, bone health, mental health, and maintaining healthy weight status, "he said. "But kids and teenagers do not necessarily think about it, they're more interested in having fun, being with their friends, and gaining new skills, so much the better."
Dr. Stephanie Walsh, pediatrician and medical director of children's wellness at Children's Healthcare in Atlanta, says she often sees parents planning long walks with their children – but that may not be the best way.
"While walking is a great activity, it's really boring for kids, so if you ask your kids to go for a walk, think of some fun things you can do along the way," Walsh said.
"Kids like to work out in bursts of activity, so they're more likely to run to the next driveway and back to you as you go further than they want to go slow with you," she said. "You can do your walk on a paper chase, you can go for fun, jump, run backwards, talk funny jokes when you walk, it will make the activity more fun and the child busy. "
Walsh added: may be beneficial for parents to model, be active and eat healthily. However, some families live in neighborhoods where one can not be sure and who have no access to healthy food. Therefore, maintaining a healthy lifestyle can be a big challenge.
"One thing I hear A lot of families are just worried about their children having safe places to play," Walsh said. "If you really do not have a safe neighborhood, there are indoor activities you can do … play some kind of active games."
On the other hand, parents of older children and teenagers may want to take a different approach to encourage their children to be physically active.
The "slippery slope" to bring teenagers to sports
Especially for girls, Walsh said, there is a huge decline in daily physical activity as soon as they enter puberty.
I usually try to talk to parents of girls even earlier – late elementary or middle school – to think about it, because we see this decline, and it's really important to keep our girls active so they can stay that way older teens and adults, "said Walsh.
" So if you're a girl's parents, it's really important to start even before youth to help your child find something they would like to do, either sport or a kind of a centricity, "she said.
Yet, parents may find it difficult to persuade teenage girls to maintain their daily physical activity without causing any body problems.
When it comes to exercise, body image problems to avoid "never associate it with weight or weight loss," said Walsh.
"Physical activity has so many other benefits that have nothing to do with weight loss ht has to do. So, when talking to your kids about this activity, talk to them about all the benefits, better sleep, better concentration, feeling better, being stronger, increased muscle mass, all the things that are really important, but don & # 39; ; You're not concentrating on weight, "she said.
" Every time you gain weight, you're starting to really go down that slippery slope. I think the same when it comes to nutrition. We're really talking about healthier things, "she said.
For example, several studies around the world have found evidence of a positive correlation between physical fitness and an increase in adolescent academic performance – a benefit that is not necessarily related to this
] The "explosion" of obesity and physical inactivity in children
"We know that physical fitness is associated with improved school performance. We know that it is associated with well-being. We know that it is a social determinant of health. So we want to increase that, "said Dr. Dan Cooper, a professor of pediatrics and founder of the Pediatric Exercise and Genomics Research Center and director of the Institute for Clinical Translational Science at the University of California, Irvine
On the other hand, it was shown to increase physical activity Obesity, a growing epidemic in the US and around the world, means that a person has too much body fat and can increase the risk of diabetes, heart disease, strokes, arthritis, and even some cancers.
"Physical fitness patterns in children to adulthood, and when they are low, can be an early indicator that the child could develop heart disease and diabetes later in life," Cooper said.
"The possibilities for children to play freely a natural environment, in the climbing, jumping, running It is simply a necessary part of the growth and development that no longer exists in our most built and often child-friendly, modern world, "he said. "We are experiencing the explosive increase in childhood obesity and physical inactivity, each of which can contribute to poor health, and we need to focus on how we can restore optimal and healthy movement to children and adolescents in adulthood."
The proportion of adolescents affected by obesity has more than tripled since the 1970s in the US CDC. It is estimated that nearly a fifth of children and adolescents are overweight – and obesity is not just an American problem.
In the United Kingdom, it is estimated that approximately every fifth child in the age of 10 to 11 years is obese. Englisch: bio-pro.de/en/region/stern/magazine/…0/index.html According to the World Health Organization, the number of overweight or obese children rose from 4 million to 9 million between 1990 and 2016.
Building a "Molecular Card" of Use for Physical Activity
Best training recommendations for children and adolescents and how exercise can affect their bodies in various ways.
"Most importantly, there are so many benefits beyond this idea of weight loss," Walsh said. "The benefits of training affect every part of your body and brain, and that's really the most important piece."
Cooper, his colleague Shlomit Radom-Aizik and other researchers from the University of California, Irvine, have joined 22 other affiliated research institutes in the US to investigate how physical activity at the molecular level can induce changes in the body of both children and adults and how these changes can improve the function of different tissues and organs.
The National Institutes of Health have honored the research The project, the Consortium for Molecular Transducers of Physical Activity, will reach approximately $ 170 million by 2022, as long as the availability of funds is not secured. The consortium launched in 2016.
"We have long understood that exercise is beneficial to our overall health, but does not fully understand the effects of movement at the molecular level," Dr. Francis Collins National Institute of Health issued a press release when the consortium was founded
"The development of a so-called molecular map of circulating signals, generated by physical activity, allows us to discover, at a fundamental level, how physical activity on our health, "he said. "This knowledge should enable researchers and physicians to develop individual, targeted exercise recommendations and better serve those who can not exercise."
For example, scientists have long known that exercise can work differently in children than in adults.
A In a small French study published Tuesday in the journal Frontiers in Physology, adolescents – most notably teenagers in this study – can regain their heart rate and recover faster than many adults after exercise.
"In our studies at the Child Health and Movement Research Center, we demonstrated that over two weeks of training with just six days of training, repeated cycle prints lasting 30 seconds, the adolescents' aerobic fitness was significantly improved and well tolerated." Williams said.
Many questions remain open as to what these and other findings mean for the molecular make-up of children and adults. The recently established National Institutes of Health consortium hopes to be able to answer them.
"I think there are such interesting things about exercise in children: the relationship to school achievement; the value of school physical fitness tests; the role of exercise in life meaning," Cooper said. "We now have the tools to study this."