Making sure kids have good muscle fitness might also benefit their school performance, according to a recent US study. Aerobic fitness has already been linked to better thinking abilities in pre-teen children, but the current study found an independent link between muscle fitness and kids' performance on memory tests as well as their math and reading skills.
"We've seen this relationship for cardiorespiratory fitness many times before," said senior author Charles H. Hillman of Northeastern University in Boston. "The relationship with strength is novel in children, but based on work with older adults, it was expected."
For the study, which was funded by Nike, 75 kids aged 9 to 11 years completed an aerobic exercise test at steady speed on a treadmill with gradually increasing incline until they were too out of breath to continue. They completed a similar test of muscular fitness with a battery of upper body, lower body and core exercises using body weight or a medicine ball, including lunges, push-ups and shoulder presses.
The kids did as many repetitions of each exercise as possible within 30 seconds while maintaining proper form.
They also completed computerized tests of working memory, algebra, geometry, reading and writing.