It is well known that having good physical fitness lowers risks for a number of health problems. But now, the first study to make the link between strength capacity in adolescents and reduced risk for diabetes, heart disease or stroke has been published in the journal Pediatrics.
Staying physically fit is an important value to instill in young people, not only because it creates healthy habits that can extend into adulthood, but also because it positively affects both short- and long-term health.
For example, a recent study suggested exercising when young helps bones to grow big and strong for life, even conferring benefits during aging.
The researchers of this latest study, led by Mark D. Peterson, research assistant professor at the University of Michigan Medical School, note that previous studies have found low muscular strength in teen boys is linked to several major causes of death in young adulthood, including suicide and cardiovascular diseases.
To delve further, the investigators examined the impact of muscle strength in sixth grade boys and girls.
In total, they assessed health data for more than 1,400 children between the ages of 10 and 12 years old, which included body fat percentage, glucose level, blood pressure, cholesterol levels and triglycerides - a type of fat that may increase risk of heart disease.
'Muscle strength equally important in children's cardiometabolic health'
Risks for diabetes and heart disease are significantly lower in strong kids, the research shows.
The data come from the Cardiovascular Health Intervention Program, which is a study of sixth graders from 17 Michigan schools between 2005 and 2008.
Using a standardized handgrip strength assessment - recently recommended by the Institute of Medicine - the researchers tested the adolescents for strength capacity.
Additionally, the participants' cardiorespiratory fitness was measured. This is how well the body is able to transport oxygen to muscles during extended exercise and how well the muscles are able to absorb and use it.
Results showed that the adolescents with greater strength-to-body-mass ratios had "significantly" lower risks of diabetes and heart disease.
Commenting on their findings, Peterson says:
"It's a widely held belief that BMI [body mass index], sedentary behaviors and low cardiovascular fitness levels are linked to diabetes, heart disease and stroke, but our findings suggest muscle strength possibly may play an equally important role in cardiometabolic health in children."
Peterson's colleague, Prof. Paul M. Gordon, from Baylor University in Texas, suggests that strengthening activities are equally as important as participation in physical activity.
The team notes that stronger kids also tended to have a lower BMI, lower body fat percentage, smaller waist circumferences and higher fitness levels. They believe theirs is the first study to show a strong link between strength and lower risks of diabetes, heart disease or stroke in adolescents - even after controlling for BMI, physical activity and cardiorespiratory fitness.
"The stronger you are relative to your body mass, the healthier you are," Peterson says.
"Exercise, sports and even recreational activity that supports early muscular strength acquisition, should complement traditional weight loss interventions among children and teens in order to reduce risks of serious diseases throughout adolescence," he adds.