Recess Is In: Daily Play Cuts Childhood Obesity

SAN ANTONIO – Vigorous aerobic exercise performed for 20 or 40 minutes, 5 days per week, improved fitness and was associated with dose-dependent benefits on insulin resistance and general and visceral adiposity in a randomized controlled trial involving 222 children who were overweight or obese and sedentary.

The intensity of the exercise appeared to be the most important factor for improving aerobic fitness, but volume of exercise was important for reducing adiposity and diabetes risk, Catherine L. Davis, Ph.D., reported at the annual meeting of the Obesity Society.

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Fitness, as measured using the adjusted mean difference in peak VO₂, was similar for 73 children randomized to 40 minutes of daily exercise (the high-dose exercise group) and 71 children randomized to 20 minutes of daily exercise (the low-dose group). Fitness was significantly greater for exercise groups compared with 78 controls. The adjusted mean difference in peak VO₂ was 2.4 mL/kg per minute from baseline to 13-weeks’ follow-up for both groups vs. the control group, said Dr. Davis of the Medical College of Georgia, Augusta.

Changes in body fat were measured using dual x-ray absorptiometry, and changes in visceral fat were measured using magnetic resonance imaging. The adjusted mean differences were -1.4% for the high-dose exercise group and -0.8% for the low-dose exercise group compared with controls. For visceral fat, the differences were -3.9% and -2.8%, respectively.

Reductions in the insulin area under the curve were measured using an oral glucose tolerance test. The adjusted mean difference was -3.56 x 10³ microU/mL for the high-dose exercise group and -2.96 x 10³ microU/mL for the low-dose exercise group compared with controls. There were no differences in outcomes based on sex or race.

The presentation of the findings coincided with their publication (JAMA 2012;308:1103-12).

Children in the study were aged 7-11 years (mean of 9.4 years) with an average body mass index of 26. Most (85%) were obese and 28% had prediabetes. The students were recruited from 15 public schools between 2003 and 2006, and were randomized to the high-dose or low-dose exercise groups or to a control group, Dr. Davis said. Six cohorts of 30-40 students participated during the study period.

Both the high- and low-dose groups exercised during an after-school program 5 days each week; exercise was vigorous, but game based, with an emphasis on intensity, fun, and safety rather than competition or skill enhancement. Average daily heart rate was calculated, and students earned bonus points for achieving a rate above 150 beats per minute. These points were used to "purchase" various prizes.

The control group did not participate in an after-school program but met monthly for a "lifestyle class," mainly for the purpose of maintaining contact for follow-up.

One-third of elementary school students in the United States are either overweight or obese, Dr. Davis said. The risk of diabetes in this population has increased as a result – often developing by puberty, with potentially dire consequences for long-term health. Prior to this study, dose-response data with respect to physical activity among children had been lacking.

"Even just 20 minutes of vigorous physical activity on a daily basis makes a big difference after just a few months," she said.

Recent data suggesting a benefit of such activity on cognition and math achievement also could convince schools to make efforts to offer daily exercise for children, she added.

This study was supported by grants from the National Institutes of Health and the Salvador de Madariaga Program of the Spanish Ministry of Education and Science. Dr. Davis and her colleagues reported having no conflicts of interest.

SAN ANTONIO – Vigorous aerobic exercise performed for 20 or 40 minutes, 5 days per week, improved fitness and was associated with dose-dependent benefits on insulin resistance and general and visceral adiposity in a randomized controlled trial involving 222 children who were overweight or obese and sedentary.

The intensity of the exercise appeared to be the most important factor for improving aerobic fitness, but volume of exercise was important for reducing adiposity and diabetes risk, Catherine L. Davis, Ph.D., reported at the annual meeting of the Obesity Society.

iStockphoto.com

Fitness, as measured using the adjusted mean difference in peak VO₂, was similar for 73 children randomized to 40 minutes of daily exercise (the high-dose exercise group) and 71 children randomized to 20 minutes of daily exercise (the low-dose group). Fitness was significantly greater for exercise groups compared with 78 controls. The adjusted mean difference in peak VO₂ was 2.4 mL/kg per minute from baseline to 13-weeks’ follow-up for both groups vs. the control group, said Dr. Davis of the Medical College of Georgia, Augusta.

Changes in body fat were measured using dual x-ray absorptiometry, and changes in visceral fat were measured using magnetic resonance imaging. The adjusted mean differences were -1.4% for the high-dose exercise group and -0.8% for the low-dose exercise group compared with controls. For visceral fat, the differences were -3.9% and -2.8%, respectively.

Reductions in the insulin area under the curve were measured using an oral glucose tolerance test. The adjusted mean difference was -3.56 x 10³ microU/mL for the high-dose exercise group and -2.96 x 10³ microU/mL for the low-dose exercise group compared with controls. There were no differences in outcomes based on sex or race.

The presentation of the findings coincided with their publication (JAMA 2012;308:1103-12).

Children in the study were aged 7-11 years (mean of 9.4 years) with an average body mass index of 26. Most (85%) were obese and 28% had prediabetes. The students were recruited from 15 public schools between 2003 and 2006, and were randomized to the high-dose or low-dose exercise groups or to a control group, Dr. Davis said. Six cohorts of 30-40 students participated during the study period.

Both the high- and low-dose groups exercised during an after-school program 5 days each week; exercise was vigorous, but game based, with an emphasis on intensity, fun, and safety rather than competition or skill enhancement. Average daily heart rate was calculated, and students earned bonus points for achieving a rate above 150 beats per minute. These points were used to "purchase" various prizes.

The control group did not participate in an after-school program but met monthly for a "lifestyle class," mainly for the purpose of maintaining contact for follow-up.

One-third of elementary school students in the United States are either overweight or obese, Dr. Davis said. The risk of diabetes in this population has increased as a result – often developing by puberty, with potentially dire consequences for long-term health. Prior to this study, dose-response data with respect to physical activity among children had been lacking.

"Even just 20 minutes of vigorous physical activity on a daily basis makes a big difference after just a few months," she said.

Recent data suggesting a benefit of such activity on cognition and math achievement also could convince schools to make efforts to offer daily exercise for children, she added.

This study was supported by grants from the National Institutes of Health and the Salvador de Madariaga Program of the Spanish Ministry of Education and Science. Dr. Davis and her colleagues reported having no conflicts of interest.

SAN ANTONIO – Vigorous aerobic exercise performed for 20 or 40 minutes, 5 days per week, improved fitness and was associated with dose-dependent benefits on insulin resistance and general and visceral adiposity in a randomized controlled trial involving 222 children who were overweight or obese and sedentary.

The intensity of the exercise appeared to be the most important factor for improving aerobic fitness, but volume of exercise was important for reducing adiposity and diabetes risk, Catherine L. Davis, Ph.D., reported at the annual meeting of the Obesity Society.

iStockphoto.com

Fitness, as measured using the adjusted mean difference in peak VO₂, was similar for 73 children randomized to 40 minutes of daily exercise (the high-dose exercise group) and 71 children randomized to 20 minutes of daily exercise (the low-dose group). Fitness was significantly greater for exercise groups compared with 78 controls. The adjusted mean difference in peak VO₂ was 2.4 mL/kg per minute from baseline to 13-weeks’ follow-up for both groups vs. the control group, said Dr. Davis of the Medical College of Georgia, Augusta.

Changes in body fat were measured using dual x-ray absorptiometry, and changes in visceral fat were measured using magnetic resonance imaging. The adjusted mean differences were -1.4% for the high-dose exercise group and -0.8% for the low-dose exercise group compared with controls. For visceral fat, the differences were -3.9% and -2.8%, respectively.

Reductions in the insulin area under the curve were measured using an oral glucose tolerance test. The adjusted mean difference was -3.56 x 10³ microU/mL for the high-dose exercise group and -2.96 x 10³ microU/mL for the low-dose exercise group compared with controls. There were no differences in outcomes based on sex or race.

The presentation of the findings coincided with their publication (JAMA 2012;308:1103-12).

Children in the study were aged 7-11 years (mean of 9.4 years) with an average body mass index of 26. Most (85%) were obese and 28% had prediabetes. The students were recruited from 15 public schools between 2003 and 2006, and were randomized to the high-dose or low-dose exercise groups or to a control group, Dr. Davis said. Six cohorts of 30-40 students participated during the study period.

Both the high- and low-dose groups exercised during an after-school program 5 days each week; exercise was vigorous, but game based, with an emphasis on intensity, fun, and safety rather than competition or skill enhancement. Average daily heart rate was calculated, and students earned bonus points for achieving a rate above 150 beats per minute. These points were used to "purchase" various prizes.

The control group did not participate in an after-school program but met monthly for a "lifestyle class," mainly for the purpose of maintaining contact for follow-up.

One-third of elementary school students in the United States are either overweight or obese, Dr. Davis said. The risk of diabetes in this population has increased as a result – often developing by puberty, with potentially dire consequences for long-term health. Prior to this study, dose-response data with respect to physical activity among children had been lacking.

"Even just 20 minutes of vigorous physical activity on a daily basis makes a big difference after just a few months," she said.

Recent data suggesting a benefit of such activity on cognition and math achievement also could convince schools to make efforts to offer daily exercise for children, she added.

This study was supported by grants from the National Institutes of Health and the Salvador de Madariaga Program of the Spanish Ministry of Education and Science. Dr. Davis and her colleagues reported having no conflicts of interest.