Research has shown that strength training can help overweight adults lower their risk of diabetes. But what about teenagers?
A small but promising study found that pudgy boys who lifted weights twice a week for four months lowered their risk for Type 2 diabetes without losing weight, a good sign that has inspired more research.
"We found this exercise to be very appealing because it's easy and kids can succeed at it very quickly. They can see and feel results," said obesity researcher Michael Goran of the University of Southern California, who led the study.
Specifically, the study found that the weightlifting boys lowered their insulin resistance, a condition in which the body fails to process blood sugar and which can lead to Type 2 diabetes. That's the most common form of diabetes. It's linked to obesity and is showing up more often in young people.
Buoyed by the study of 22 Latino boys, Goran is undertaking a larger, government-funded trial of 120 minority adolescents of both sexes. Minorities are at particularly high risk for Type 2 diabetes.
When it develops early in life, experts say it has many more years to do damage and can lead to premature complications, including heart disease, blindness, kidney failure, or even death.
Previous studies have shown adults can stave off diabetes through a combination of strength training and aerobic exercise. Strength training has been known to build bone and muscle, which help the body burn more calories. But little research has been done on the effect of weight training on at-risk teens.
The USC study recruited 22 overweight Latino males, age 14 to 17, who either worked with a personal trainer or were assigned to a non-exercising group.
The teens in the exercise group performed resistance training twice a week that included weights, leg presses, bench presses and bicep curls.
After four months, researchers found the exercise group significantly reduced their insulin resistance. Ten out of 11 boys improved their insulin resistance while 6 out of 10 in the control group showed a decline. An 11th person failed to show up for post-study testing.
Although the boys' weight didn't change, they did have less body fat and more lean muscle, researchers found.
The study was published in the July issue of Medicine and Science of Sports Exercise, the journal of the American College of Sports Medicine. It was partly funded by the Thrasher Research Fund, a private organization that contributes to pediatric research.
Dr. Larry Deeb, president of medicine and science at the American Diabetic Association, said he was impressed by how the teens showed improved insulin sensitivity in a short period of time. While more research is needed, he said, the study indicates it doesn't take a lot of effort to reduce one's diabetes risk.
"One of the things that we have to convince parents is that it's doable," said Deeb, who had no role in the research. "Some change makes all the difference in the world."
Goran, who has a grant from the National Institutes of Health, is recruiting 120 overweight Latino and black teens for a larger study that will examine how weight training and nutrition affects diabetes risk. Results are expected by the middle of next year.
By Alicia Chang, AP Science Writer
(Copyright 2006 by The Associated Press. All Rights Reserved.)