Analysis of Magnitude and Direction of Body Composition Asymmetries in Male Brazilian Jiu-Jitsu Athletes: Pilot Study

In order to optimize body composition and its components, it is of interest to analyze inter-limb asymmetries in athletes of popular combat sports such as Brazilian Jiu-Jitsu (BJJ). This study aimed to assess the magnitude and direction of body composition asymmetry in competitive male BJJ athletes. Seventeen experienced and competitive male BJJ athletes (age 34.59 ± 8.00 years, 172.94 ± 5.46 cm, BJJ experience 7.88 ± 5.57 years, and 3.71 ± 1.05 days of weekly volume training), including Guard Fighters (<i>n</i> = 7) and Pass Fighters (n = 10), participated in this study. In a single session, whole-body and segmental upper limb and lower limb body composition (BC) was assessed utilizing dual-energy X-ray absorptiometry (DXA). The assessment included total mass (TM), fat mass (FM), fat mass percentage (%FM), fat-free mass (FFM), and bone mineral content (BMC). Absolute differences between limbs were analyzed using a paired <i>t</i>-test. A comparison of BC asymmetries according to combat styles was conducted using an independent <i>t</i>-test. The effect size (ES) was interpreted as Cohen's d. The main results revealed significant asymmetries in the upper limbs (ULs) of the total group; greater values were found on the left side for TM (<i>p</i> = 0.009, ES = 0.725), FM (<i>p</i> = 0.016, ES = 0.650), FFM (<i>p</i> = 0.026, ES = 0.594), and BMC (<i>p</i> < 0.001, ES = 0.993). In Pass Fighters, differences favored the right side in TM (<i>p</i> = 0.003, ES = 1.277), FM (<i>p</i> = 0.009, ES = 1.039), FFM (<i>p</i> = 0.011, ES = 1.000), and BMC (<i>p</i> < 0.001, ES = 1.916). In contrast, Guard Fighters showed no discrepancies in these parameters. No notable disparities were observed in the lower limbs. This pilot study reveals that BJJ athletes present significant asymmetries in BC, particularly in the ULs, with a marked predominance on the right side, especially in Pass Fighters.