Study Finds Body Mass Index Alone Does Not Accurately Reflect Trunk Strength and Endurance

A new study conducted by researchers at institutions including the Slovak University of Technology in Bratislava and Comenius University examined how well body mass index reflects functional trunk capacity in young adults. The investigation assessed 199 male university students, measuring their body mass index, maximal isometric back extensor strength, plank-based trunk endurance, and sagittal spinal posture. The authors used exploratory cluster analysis to identify distinct functional profiles among the participants.

The findings indicate that body mass index has a moderate negative association with plank endurance and a weak positive association with maximal isometric back extensor strength. Cluster analysis further separated the cohort into distinct functional profiles that correlated with self-reported physical activity frequency, though overall separation was limited. The study notes that spinal curvatures and reasons for terminating the plank test did not differ significantly across the identified groupings.

What to know: Because plank endurance and back strength represent separate aspects of trunk function that are only partly tied to body mass index, experts suggest that multidimensional fitness evaluations are necessary for a complete understanding of physical capacity. Readers should consult a qualified healthcare or fitness professional before making major changes to their exercise or health routines.