Key body size/shape predictors of physical fitness in Saudi College-aged males: Role of the body roundness index

TL;DR

This study finds that body shape and size indicators like the body roundness index better predict physical fitness in Saudi male students than BMI.

Contribution

The study introduces the body roundness index as a better predictor of cardiorespiratory endurance than BMI.

Findings

Overweight and obese groups showed significantly lower fitness test performance than normal weight groups.

Body roundness index (BRI) explained up to 56% of the variance in VO2max performance in obese individuals.

Waist-to-height ratio and hip circumference improved shuttle-run performance prediction in obese participants.

Abstract

Physical fitness, a crucial factor in health and well-being, is influenced by an individual’s body composition. This study aimed to identify the key body size/shape predictors of fitness test performances among university-level students with diverse weight categories. This cross-sectional study involved 495 healthy, recreationally active male university students aged 18−23 years, categorized into normal weight (NORMW, n = 256), overweight (OVERW; n = 156), and obese (OB; n = 124) groups based on their body mass index (BMI). Anthropometric measurements including weight, height, BMI, waist and hip circumference (WC and HC), waist-to-hip and waist-to-height ratios (WHR and WHtR), body roundness and shape body indexes (BRI and ABSI) were recorded. The shuttle-run, push-ups, 20m Multi-Stage shuttle-run, and sit-and-reach tests were performed. The OB and OVERW groups performed significantly lower fitness test performances than the NORMW group (medium-to-large effect size). The correlation matrix showed that all anthropometric measures correlated with test performances, except for the sit-and-reach in the OB group and the shuttle-run in the NORW group. Higher WHtR and HC improved shuttle-run performance predictability in the OB group (R2 = −0.29), while WC and HC, and WC and BMI improved push-up predictability in the OB (R2 = −0.38) and OVERW (R2 = −0.24) groups. BRI was the best indicator of VO2max performance, accounting for 56%, 42%, and 32% of its variance in OB, OVERW, and NORMW groups, respectively. The BRI is proposed as a potential alternative to BMI for evaluating cardiorespiratory endurance performance, enabling individual monitoring.

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