Most parents, teachers, and clinicians would agree that it's important for children to be active. But, what about muscle strength? When it comes to risk factors for metabolic diseases such as type II diabetes, is there a distinction to be made between active and strong? An interesting study by Gomes and colleagues published in the American Journal of Human Biology tried to tackle this issue. The researchers studied 378 Portuguese children between the ages of 9-11 years. Physical activity was assessed for a seven day period, and muscle strength was tested via handgrip dynamometry (normalized to body weight). The children were divided into low and high physical activity and strength groups using the 50th percentile scores as cutoffs. Each child's metabolic risk was computed from waist circumference, blood pressure, cholesterol, and blood glucose measurements. Not surprisingly (and sadly), 65% of the children were classified as inactive. Interestingly, the researchers reported that the children with the highest muscle strength had the lowest metabolic risk, even after adjustment for physical activity. In addition, there were important differences among the groups of children, such as lower waist circumference and metabolic risk for the active + strong group compared to the active + weak group.
Although the work of Gomes et al. (2017) was not without some limitations, these findings suggested that muscle strength is an important predictor of metabolic health in children. Moreover, a distinction can be made between kids that are both active and strong compared to just active.