Longer exercise provides added benefit to children's health
Twenty minutes of daily, vigorous physical activity over just three months can reduce a childs risk of diabetes as well as his total body fat -- including dangerous, deep abdominal fat -- but 40 minutes works even better, according to research by Dr. Catherine Davis, clinical health psychologist at the Institute of Public and Preventive Health at Georgia Health Sciences University. Credit: Phil Jones, GHSU photographer
Twenty minutes of daily, vigorous physical activity over just three months can reduce a child's risk of diabetes as well as his total body fat - including dangerous, deep abdominal fat – but 40 minutes works even better, researchers report.
"If exercise is good for you, then more exercise ought to be better for you and that is what we found for most of our outcomes," said Dr. Catherine Davis, clinical health psychologist at the Institute of Public and Preventive Health at Georgia Health Sciences University.
Pediatric and adult studies have shown the metabolic benefits of aerobic activity but had yet to dissect differences in the dose response, or the amount of activity needed to elicit a given benefit. The study published in the Journal of the American Medical Association looked at 222 overweight, previously inactive 7- to 11-year olds in the Augusta, Ga., area and found more is better.
"Obesity is a growing public health crisis that is affecting youth throughout the United States, and we know that obesity can contribute to the development of type 2 diabetes," said Dr. Michael Lauer, Director of the National Heart, Lung and Blood Institute Division of Cardiovascular Sciences of the National Institute of Health. "This research adds to the body of evidence that physical activity improves children's health, that longer periods of exercise provide a greater benefit and that increased physical activity among overweight and obese children could stave off the onset of type 2 diabetes."
A third of the study participants maintained their typically sedentary lifestyle; a third began a 20-minute heart-rate-raising, after-school exercise routine for three months; and a third exercised for 40 minutes after school.
Children who exercised for 40 minutes had a 22 percent reduction in insulin resistance versus the controls, while the 20-minute group experienced an 18 percent reduction, said Davis, the study's lead author.
The extra 20 minutes also helped the children lose more total body fat and visceral fat while fitness, which appeared driven by intensity rather than duration, gained a similar boost from both time periods. Benefits were gained without restrictive diets and worked equally well in black and white boys and girls.
Davis' research team kept both groups moving with running and tag games and modified sports. "Regulation sports tend to have kids standing around a lot waiting for the ball. We had enough balls so everyone was moving all the time," she said. They kept it fun, giving non-food rewards, such as small toys, for children who kept their heart rates high. "It had to be fun or they would not keep coming," said Davis, noting the 94 percent retention rate of study participants.
She hopes the evidence of the solid health benefits of a fun, vigorous and relatively short exercise routine will be used to design public health interventions for a society in which one-third of elementary school children are overweight.
"It's practical in the sense that we were able to quantify the dose required to make these changes," Davis said. "If you are able to get kids active for 20 minutes every day in school, whether through physical education or taking a running break during lunch, that can make a real difference." She noted that while schools are a great place to start, jam-packed curricula likely mean a 40-minute exercise routine will require after-hours programs as well.
"You can reach a lot of kids by making changes at school," Davis said. "We don't want this to just be for athletic or coordinated kids but for all kids, especially the ones who are less likely to be on a sports team."
Childhood obesity rates in the United States have been climbing for more than a decade. While they seem to be plateauing, the unprecedented levels have serious consequences for children's health and longevity, Davis said. A primary example is the emergence of type 2 diabetes, previously considered an adult, lifestyle-related problem with serious implications for cardiovascular health and more. One of the first indications of trouble is increased insulin resistance, how much insulin the pancreas must produce to enable glucose circulating in the blood to become energy for the cells. In this study, researchers showed a benefit of 40 minutes of daily exercise on the disposition index – the ratio of insulin resistance to the body's ability to secrete insulin – a proven predictor of diabetes development in adults.
"When your body is no longer able to secrete enough insulin to overcome your body's resistance to it, that's when it becomes diabetes," Davis said, noting that in insulin resistance, pancreases must work overtime producing extra insulin to convert excess blood glucose to usable energy. Without sufficient insulin, a vicious cycle results as energy-starved cells increase the appetite and people eat more creating even more glucose to convert. "Exercise basically gives the pancreas a break and could prevent or delay type 2 diabetes as long as people remain active," Davis said. Longer-term and follow-up studies are needed to find out what happens with these children over time and how to help them sustain a healthy lifestyle.
In 2005, a federal panel, co-chaired by Dr. William B. Strong, a pediatric cardiologist and retired Professor at the Medical College of Georgia at GHSU, recommended 60 minutes or more of daily vigorous physical activity for school-age children. The supervised 40-minute exercise sessions in the study likely resulted in a similar amount of cumulative activity, Davis said. "And, unfortunately 40 minutes is a lot more activity than many children are getting these days."
Journal reference: Journal of the American Medical Association
Provided by Georgia Health Sciences University
- Exercise helps overweight children reduce anger expression Nov 24, 2008 | not rated yet | 0
- Exercise can produce healthy chatter between bone, fat and pancreatic cells Sep 19, 2011 | not rated yet | 0
- Childhood obesity linked to stiff arteries Apr 12, 2010 | not rated yet | 0
- Exercise helps overweight children think better, do better in math Feb 10, 2011 | not rated yet | 0
- Regular exercise reduces depressive symptoms, improves self-esteem in overweight children Mar 18, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Artemio Martinez balanced his corpulent frame on a stool in a Mexico City street taco stand, downing a sweet soda and eating a final pork-filled corn tortilla.
Health 46 minutes ago | not rated yet | 0
People eating at fast food restaurants largely underestimate the calorie content of meals, especially large ones, according to a paper published today in BMJ.
Health 12 hours ago | not rated yet | 0
Don't doubt it when a woman harried by hot flashes says she's having a hard time remembering things. A new study published online in Menopause, the journal of The North American Menopause Society (NAMS), helps confirm with o ...
Health 13 hours ago | not rated yet | 0
The Senate has overwhelmingly rejected an amendment allowing states to require labeling of genetically modified foods.
Health 14 hours ago | not rated yet | 1
The World Health Organization voiced deep concern Thursday over the SARS-like virus that has killed 22 people in less than a year, saying it might potentially spread more widely between humans.
32 minutes ago | 5 / 5 (1) | 0
(AP)—Researchers examining the incidence of brain cancer at jet engine manufacturer Pratt & Whitney in Connecticut say they have found no statistically significant elevations in the rate of cancer among workers.
22 minutes ago | not rated yet | 0
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
13 hours ago | 4.8 / 5 (6) | 0 |
The British Menopause Society and Women's Health Concern have today released updated guidelines on Hormone Replacement Therapy (HRT) to provide clarity around the role of HRT, the benefits and the risks. The new guidelines ...
2 hours ago | not rated yet | 0
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
18 hours ago | 4.5 / 5 (10) | 1 |
Teams of highly respected Alzheimer's researchers failed to replicate what appeared to be breakthrough results for the treatment of this brain disease when they were published last year in the journal Science.
16 hours ago | 5 / 5 (1) | 2 |