Bioelectrical impedance vector evaluation (BIVA) in college athletes


Examine design

This cross-sectional research is a part of the macroproject entitled “Results of a sports activities season on the mobile well being of athletes of various modalities” carried out on the Federal College of Santa Catarina (UFSC), positioned within the metropolis of Florianópolis, Santa Catarina, Brazil. Knowledge assortment was carried out between the months of September and November 2017. The analysis was accredited by the Ethics Committee for Analysis with Human Beings at UFSC, beneath the quantity: 2.308.476. All college athletes signed the Free and Knowledgeable Consent Kind.


The inhabitants was composed of college athletes from completely different sports activities, usually enrolled in Undergraduate and Graduate Research at UFSC. The research pattern was comfort, so that each one athletes who participated in coaching for sports activities competitions, aged 18 to 35 years previous, of each sexes, have been recruited. The full variety of athletes linked to the sports activities modalities was 179, based on an important college competitors within the state.

The inclusion standards have been: 1) athletes aged 18 to 35 years age, of each sexes; 2) usually enrolled at UFSC; 3) take part in at the least one state, regional, sports activities competitors.

nationwide and / or worldwide all through a sporting season within the 12 months 2017. The exclusion standards have been: 1) athletes who have been submitted surgical procedures that alter physique composition, akin to bariatric surgical procedure; 2) skilled athletes, or those that now not had a relationship with UFSC. Athletes who rejected the invitation have been thought-about as refusals to take part within the research through the information assortment interval. The athletes who agreed to take part within the research, however didn’t attend the assembly information assortment, as much as three makes an attempt have been thought-about as losses. Thus, six athletes have been thought-about refusals, and 6 have been thought-about as losses. Thus, 167 athletes have been evaluated, 92 have been male [athletics (n = 11), badminton (n = 02), basketball (n = 01), field football (n = 30), futsal (n = 14), hockey grass (n = 03), judo (n = 08), swimming (n = 07), skateboard (n = 01), tennis (n = 4) and volleyball (n = 11)], and 75 females [athletics (n = 06), badminton (n = 01), flag football (n = 13), futsal (n = 20), handball (n = 09), grass hockey (n = 04), judo (n = 06), skateboard (n = 03), tennis table (n = 01) and volleyball (n = 12)].

The modality practiced was categorized into group sports activities (basketball, flag soccer, discipline soccer, futsal, handball, discipline hockey and volleyball), and particular person and / or double sports activities (observe and fields, badminton, judo, swimming, skateboarding and desk tennis). Staff sports activities are characterised by intermittent hundreds, with the cardio system predominating [20]. Alternatively, particular person or collective sports activities primarily use the anaerobic system, which might affect the form and physique measurement traits [12]. As well as, the lack of physique water will be accentuated in particular person sports activities during which sports activities are divided into weight courses, akin to judo [21]. The observe time, the variety of sports activities competitions per 12 months and the presence of accidents have been obtained by way of the appliance of an anamnesis kind, answered individually by every athlete (Fig.  1).

Fig. 1

Flowchart of the research sampling course of

Bioelectrical impedance vector evaluation (BIVA)

With a purpose to consider BIVA, the bioelectrical impedance (BIA) technique was used. The mannequin used was InBody® 720 (Biospace, Los Angeles, USA), multi-frequency with eight electrodes, measuring impedance in 5 frequencies (1, 50, 250, 500 and 1000 kHz) and Xc in three (5, 50 and 250 kHz). The method supplied impedance and reactance information at frequency of fifty kHz, calculating the resistance worth, after which the part angle utilizing the arc tangent system (Xc / R) × 180 ° / π3, with values expressed in levels. The BIA mannequin used introduced acceptable reproducibility and accuracy stage for the estimation of physique composition tissues at frequency of fifty kHz, when in comparison with plethysmography and twin X-ray absorptiometry [22]. As well as, the producer reinforces that prime accuracy stage is obtained by following the right measurement procedures.

Primarily based on BIVA values, confidence and tolerance ellipses have been created. Confidence ellipses comprise the 95% confidence interval for the vector means discovered by plotting the imply of elements of the connection between R and Xc by top (meters) measured in a bunch of people [23]. The pattern imply is introduced as an estimate of outcomes that might be obtained if the whole inhabitants was studied. Confidence intervals are used to confirm whether or not a imply is considerably completely different from a hypothetical worth or a comparability inhabitants [23]. Tolerance ellipses are graphic analyses of particular person or the three ellipses: the median, the third quartile and the ninety fifth percentile, that are areas that embrace 50, 75 and 95% of particular person factors, respectively [23]. Thus, the tolerance graph permits a extra detailed classification of the vector place of the person impedance (one level) within the R / Xc chart by the use of its distance from the imply vector of the reference inhabitants [23].

For BIA analysis, top was measured by the protocol of the Worldwide Society for the Development of Kinanthropometry (ISAK) by level-1 researcher utilizing AlturaExata® stadiometer (Belo Horizonte, Brazil), with 1-mm decision. Throughout analysis, athletes remained in orthostatic place, holding two levers and with their toes positioned on a platform. The analysis lasted about 2 min. All athletes have been instructed to comply with pre-test suggestions, which included: fasting for at the least 4 h, mild clothes (bikini, swimwear, prime, lycra shorts), barefoot, with out using earrings and / or rings and / or any form of steel, abstaining from intense bodily exercise the day before today, abstaining from drinks with excessive caffeine content material within the earlier 12 h. Feminine athletes who have been within the menstrual interval on the day of the analysis have been rescheduled for an additional time. The evaluations befell within the morning, between 8 a.m. and 12 p.m.

Statistical strategies

For the descriptive evaluation of information, imply and normal deviation have been calculated. Kurtosis and asymmetry have been used to confirm information normality (interval between − 2 and + 2). The Pupil’s T-test was used to determine variations between group and particular person sports activities athletes. For confidence ellipses, R and Xc values have been standardized by top (meters) and variations between teams have been analyzed by the T2 Hotelling take a look at. The T2 Hotelling take a look at was designed to check inhabitants imply vectors. For tolerance ellipses, R and Xc values standardized by top for all pattern and the means standardized in z-score have been used. All analyses have been carried out utilizing BIVA 2002® software program (Microsoft, Padova, Italy), adopting p ≤ 0.05.