Somatotype and Bioimpedance Vector Analysis: A New Target Zone for Male Athletes

Abstract

Background: Bioelectrical impedance vector analysis (BIVA) is a body composition assessment method based on the interpretation of the raw bioimpedance parameters. While it was initially proposed in clinical settings, its use in the sports field has grown considerably. The aim of this study was: (i) to explore the role of somatotype on BIVA patterns and (ii) to propose a new target zone to improve BIVA analysis in ball games athletes. Methods: One hundred and sixty-four male volleyball, soccer, and rugby players (age 26.2 ± 4.4 yrs; body mass index (BMI) 25.4 ± 2.4 kg/m2) were included in this study. Somatotype and BIVA were measured from anthropometric and bioelectrical data, respectively. Results: Forty-six athletes were classified with an endomorphic mesomorphic somatotype, 26 showed a balanced mesomorphy, 55 were ectomorphic mesomorph, 10 resulted as mesomorph ectomorphs, 13 with a mesomorphic ectomorph somatotype, and in 14 athletes a balanced ectomorphy was assessed. The results of the Hotelling’s T2 test showed significant differences in BIVA patterns for the endomorphic mesomorph group (p < 0.001) in comparison with all the other groups, while mesomorphic balanced athletes presented a more inclined vector compared to the athletes with a balanced ectomorphy (p < 0.003). In addition, the endomorphic mesomorph group showed a greater BMI (p < 0.001) with respect to the athletes grouped in the other somatotype categories. Discriminant analysis revealed two significant functions (p < 0.001). The first discriminant function primarily represented differences based on the bioelectrical standardized resistance parameter (R/H) measure, while the second function reflected differences based on the bioelectrical standardized reactance parameter (Xc/H). Conclusions: Athletes presenting a higher endomorphic component have a lower vector, whereas those with a larger mesomorphic component display higher vector inclinations on the R-Xc graph. We propose a new target zone to improve the interpretation of BIVA analysis in athletes engaged in team sports.

Body Water Content and Morphological Characteristics Modify Bioimpedance Vector Patterns in Volleyball, Soccer, and Rugby Players

“…In particular, athletes with a higher TBW (Q4) showed a mean vector positioned lower than the other athletes ( Figure 2 ). This is in line with previous studies that observed vector length and its changes to accurately reflect changes in TBW using dilution techniques to assess water and its compartments [ 17 , 20 , 21 ]. In addition, when the mean vectors for each somatotype category were plotted on the R-Xc graph, it was possible to observe how athletes with a higher mesomorphic component showed a vector tending to be more left in the graph.…”

“…Rakovi’c et al [ 32 ] showed how mesomorphic features are linked to individual sports that require higher muscle strength, while ectomorphy is predominant in runners [ 33 ], especially those involved in long distance. In previous research [ 21 ], it was highlighted how R/H and Xc/H were able to discriminate somatotypes. However, if we consider this new and more individual approach, considering the TBW values, probably some of those athletes needed to be revised, since body fluids have a great influence on the vector position.…”

“…In fact, the vector length is inversely proportional to TBW, while the lateral displacements of the vector are directly correlated with the ICW/ECW ratio [ 17 , 18 , 19 , 20 ]. In addition to these body composition variables, Campa et al [ 21 ] have recently suggested that the somatotype also influences vector position in the R-Xc graph, where athletes with higher mesomorphic and endomorphic components are positioned more to the lower-left than athletes with a dominant ectomorphy. However, as the content of total body fluids is greatly associated with the vector, correct discrimination in the R-Xc graph based on somatotype categories may be compromised.…”

“…The bioelectric values and the vector position reflect body composition; in particular, the phase angle (PhA), obtained as the arctangent of Xc/R, correctly mirrors the ICW/ECW ratio [ 17 , 18 , 19 , 20 ]. In fact, athletes with a high PhA are positioned to the left portion in the R-Xc graph [ 21 , 22 ], and increases in muscle mass, body cell mass, and, therefore, ICW lead to vector shifts further to the left over time [ 23 , 24 ]. A high muscularity is observed in subjects with a high PhA or in those whose somatotype shows a dominant mesomorphic component [ 21 , 22 ], as mesomorphy characterizes skeletal muscle features [ 25 ]; moreover, both PhA and somatotype can be modified with nutrition and exercise [ 23 , 26 ].…”

“…In fact, athletes with a high PhA are positioned to the left portion in the R-Xc graph [ 21 , 22 ], and increases in muscle mass, body cell mass, and, therefore, ICW lead to vector shifts further to the left over time [ 23 , 24 ]. A high muscularity is observed in subjects with a high PhA or in those whose somatotype shows a dominant mesomorphic component [ 21 , 22 ], as mesomorphy characterizes skeletal muscle features [ 25 ]; moreover, both PhA and somatotype can be modified with nutrition and exercise [ 23 , 26 ]. However, to the best of our knowledge, no study has explored the associations between somatotype and PhA, while analyzing the influence of morphology on the vector position for similar TBW values in athletes.…”