Active and strong: physical activity, muscular strength, and metabolic risk in children

Objectives: This study explored the associations among physical activity, muscular strength, and metabolic risk among children.

Methods: The sample included 378 Portuguese children (213 girls; 9-11 years). Moderate-to-vigorous physical activity was assessed by accelerometry and children were classified as active (≥60 min/day) or insufficiently active (<60 min/day). Static strength was expressed as the ratio of handgrip strength/body weight and used to classify children as having high (≥P50) or low (<P50) muscular strength. Children were classified into four groups: active and high strength, active and low strength, insufficiently active and high strength, insufficiently active and low strength. A continuous metabolic risk score was computed from cardiometabolic risk factors.

Results: In general, the insufficiently active and low strength group had the worst metabolic risk score, and the active and high strength group had the best. Significant differences were found within physical activity groups for metabolic risk: children classified as "active and high strength" and "insufficiently active and high strength" had better metabolic risk scores than "active and low strength" and "insufficiently active and low strength", respectively.

Conclusions: Muscular strength has a relevant role in attenuating the association between physical inactivity and metabolic risk in children; a further benefit was identified in children with high physical activity and high muscular strength.