Proposal of a New Parameter for Evaluating Muscle Mass in Footballers through Bioimpedance Analysis

Abstract

The evaluation of muscle mass in athletes correlates with sports performance directly. Bioimpedance vector analysis is a growing method of assessing body composition in athletes because it is independent of predictive formulas containing variables such as body weight, ethnicity, age, and sex. The study aims to propose a new parameter (Levi’s Muscle Index, LMI) that evaluates muscle mass through raw bioelectrical data. A total of 664 male footballers underwent bioimpedance assessment during the regular season. LMI was correlated with body cell mass (BCM) and phase angle (PA) to establish efficacy. The footballers were 24.5 ± 5.8 years old, 180.7 ± 5.9 cm tall and weighed 76.3 ± 7.1 kg. The relationships were: LMI-BMI: r = 0.908, r2 = 0.824, p < 0.001; LMI-PA: r = 0.704, r2 = 0.495, p = 0.009 and PA-BCM: r = 0.491, r2 = 0.241, p < 0.001. The results obtained confirm that LMI could be considered a new parameter that provides reliable information to evaluate the muscle mass of athletes. Furthermore, the higher LMI-BCM relationship than PA-BCM demonstrates specificity for muscle mass evaluation in athletes regardless of body weight, ethnicity, age, and sex.

Bioimpedance Patterns and Bioelectrical Impedance Vector Analysis (BIVA) of Body Builders

“…Male bodybuilders were statistically different compared with the general male population [ 19 ] and athletic reference [ 20 ]. Specifically, they fell more to the left than the general population (T 2 < 168.8; D = 2.14; p < 0.001) and to the left and down than the athletic population (T 2 < 17.7; D = 0.95; p < 0.001) ( Figure 1 b) and their specific the 50%, 75%, and 95% tolerance ellipses are represented in Figure 1 c. On the other hand, female bodybuilders compared with the general female population [ 18 ] and athletic reference [ 20 ] fell to the left of the general population (T 2 < 67.3; D = 1.64; p < 0.001) but did not differ from the athletic population (T 2 < 1.9; D = 0.27; p < 0.40) ( Figure 1 d,e). The specific 50%, 75%, and 95% tolerance ellipses of female natural bodybuilders are represented in Figure 1 f. The LMI value of male bodybuilders is 3.7 ± 0.6, while for female bodybuilders, it is 2.3 ± 0.4.…”

“…In this context, the evaluation of muscle mass using the Levi Muscle Index (LMI), a new parameter based on raw bioelectrical parameters, is also useful. In detail, the male bodybuilders in this study show higher values than male elite soccer players (3.7 ± 0.6 vs. 3.08 ± 0.35, respectively) [ 18 ].…”

“…In order to verify muscle mass through raw bioelectrical values, the Levi Muscle Index, defined as LMI = (PhA × H)/R, was calculated [ 18 ]. BIA measurements were all taken by the same-trained investigator to avoid inter-observer errors.…”

Morphological Characteristics of Elite International Soccer Referees: Somatotype and Bioelectrical Impedance Vector Analysis

“…For example, Matias et al [33] developed a bioimpedance-based model for fat-free mass prediction based on the four-compartment model in a sample of national level athletes that can be used to overcome problems arising when measuring adult elite athletes. Similar considerations can be raised for other compartments such as muscle mass [34] and total body water and its distribution into the intra-and extra-cellular compartment [35]. From this point of view, a solution is to adopt specific equations for the investigated population [11].…”