Adequate sleep, strength training leads to healthier lifestyle for kids

Teens are known to be busy with extracurricular activities, schoolwork and socializing. All that activity leads to late nights and not enough sleep. Lack of sleep can negatively affect teens' health, especially those that are obese.

In a recent study in the Journal of Pediatrics, Dr. Paul M. Gordon, professor and chair of the health, human performance and recreation department in Baylor's School of Education, found that insufficient amounts of sleep in obese adolescents increased the risk for cardiovascular disease and diabetes.

"In the United States more than 30 percent of adolescents are overweight and more than 15 percent are obese, placing them at increased risk for heart disease and diabetes," Gordon explained. "This finding was independent of commonly known risk factors like physical activity and body composition. It suggests a need to consider objective sleep measurements among those considered to be already at risk for cardiometabolic diseases, such as obese adolescents."

Gordon and a team of researchers from the University of Michigan Health System conducted measurements on 37 obese adolescents, ranging in age from 11 to 17. The teens all had a body mass index (BMI) above the 95th percentile.

Tracking sleep, activity

Using cholesterol and blood sugar, body mass index (BMI), blood pressure and waist circumference, the researchers calculated the teens' cardiometabolic score, the higher the score, the higher the risk. The study participants also wore a physical activity/sleep monitor for seven days, which allowed researchers to track their sleep and activity.

Gordon and his team of researchers found that about only 30 percent of the participants met the minimum recommendation of being physical active at least an hour a day, which is common in this population.

The majority of participants slept an average of 7 hours per night, which is less than the National Sleep Foundations' recommendations of 8.5 to 9.5 hours per night for youth ages 10-17. Only five out of the 37 adolescents in the study actually slept 8.5 hours a night.

Gordon's research is a step toward understanding the link between sleep and teen obesity.

"While we don't yet understand the mechanisms of this relationship, this study sheds new light on the importance of appropriate sleep amounts in higher-risk populations like obese adolescents," Gordon said. "Clinically, it might be prudent to think about monitoring sleep patterns in adolescents who are already considered at risk for heart disease and diabetes."

Reducing risk through strength building

Continuing on his study of cardiometabolic diseases and youth, Gordon conducted a study on how early strengthening activities can lead to a decrease in cardiometabolic health risks in children and adolescents.

Until recently, treatment for adolescent obesity and associated health problems has focused mostly on diet changes and aerobic exercise such as walking or swimming. But Gordon's recent research study appearing in the April edition of Pediatrics concludes that adding strength-building exercises will help adolescents reduce the risks of heart disease, diabetes and other health problems.

With these findings, Gordon and his research team demonstrated for the first time that strength capacity is robustly associated with lower cardiometabolic risk in adolescents, even after controlling for the influence of BMI, physical activity participation, and cardiorespiratory fitness.

The findings contradict a popular belief that only high BMI measurements, low cardiorespiratory fitness, and excessive sedentary behaviors are the primary drivers of cardiometabolic abnormalities, Gordon said.

"Our study bolsters support for early strength acquisition and strategies to maintain healthy BMIs and body compositions among children and adolescents," Gordon said. "Unfortunately, to date, most clinical reports have focused on the safety or efficacy of strength training in pediatrics, rather than its potential viability for health outcomes."

Gordon and his team collected data from over 1,400 boys and girls, ages 10-12. Results of the study showed that boys and girls with greater strength-to-body mass ratios had lower BMIs, lower percent body fat, smaller waist circumferences, higher levels of cardiorespiratory fitness, and significantly lower clinical markers of risk.

To reach those conclusions, researchers used measurements of the child's cardiometabolic risk components—percentage of body fat, fasting glucose levels, blood pressure, plasma triglycerides levels and HDL cholesterol.

The research team examined numerous potential predictors of positive and negative health, such as fitness, physiologic parameters and behavioral factors. "We were specifically interested in how BMI, physical activity, cardiorespiratory fitness and muscular strength were related to the cardiometabolic risk," Gordon said.

Combined with other recent research, Gordon said the results of this study provide "strong support" for the use of strengthening exercises to supplement traditional weight loss interventions among pediatric populations.