Application of Bioelectrical Vector Analysis

in Professional Soccer Players

BIVA in Sport

Gabriele Mascherini, Andrea Cattozzo, Cristian Petri, Lorenzo Francini and Giorgio Galanti

Sports Medicine Department, University of Florence, largo Brambilla 3, Florence, Italy

Italian Football Athletic Trainers Association, via D’Annunzio, Florence, Italy

Keywords: Bio Impedance, Soccer, Sport Training, Vector Analysis.

Abstract: Soccer is a sport team with a discontinuous nature of physical effort and the duration of the regular season is

10 months length. Hydration status, water consumption are aspects of human performance debate in recent

years and it’s well demonstrated as a reduction of total body water impairs endurance ability. Bio

impedance is a useful methods to assess total body water, in addition recent studies reports a new approach

in the evaluation of hydration status independently from body weight. The aim of the study was to

determine changes of the bioelectrical impedance throughout a soccer season. Bioelectrical parameters of a

Italian professional football team were recorded eight time during a regular season. The detection were

carried out following the standard tetra polar method. Twenty-five male soccer players were submitted at

BIA measurement, but only eleven athletes took part in all eight sessions detection. The data recorded by

conventional BIA processing didn’t show any statistical differences in weight, hydration and cellular

masses. Bio Impedance Vector Analysis (BIVA) shows a high significance in Anova test for the values of

Xc (p<0.01) and PA (p<0.001), no difference in Rz among eight measurements. Body composition and

hydration status in footballers are generally well and the variations in conventional BIA are minimal.

Therefore BIVA in this population may give specific information for physiological changes for training

dues. A regular bio impedance assessment in athletes is desirable to follow adaptations to training loads.

1 INTRODUCTION

Many sports such as football, rugby and basketball

have a discontinuous nature of physical effort,

consisting in prolonged periods of exercise with

repeated intermittent high intensity bursts

interspersed with lower-intensity exercise: football is

a sport team and his sudden changes in intensity is

due to its intrinsic nature dictated by tactical and

technical reasons (Di Salvo V, 2008).

A regular season in professional Italian soccer

league during 10 months and the level of exercise

could induces muscle-tendon injuries, overuse

syndromes, over-reaching and even over-training

syndromes causing days of absence from the sport

(Bahr R., 2009; Kellmann M., 2010).

During matches and training, soccer players are

exposed to high physical stress (Bangsbo J, 2006),

which is suggested to influence body composition

and hydration status.

Hydration status, water consumption and the effects

of hypo hydration on aspects of human performance,

health and wellbeing have been the topic of much

public and scientific debate in recent years. The

effect of body water balance on aspects of exercise

performance has been extensively researched and in

recent years has been reviewed widely

 (Cheuvront

SN, 2003; Coyle EF, 2004; Judelson DA, 2007)

.

orrect rehydration is sufficient to limit body mass

loss to 1.4%, prevents a reduction in soccer skill

performance (McGregor S, 1999) in comparison

with performance when body mass is reduced by

2.5%. Body water loss in human subjects results in

fluid losses from both the intracellular and

extracellular fluid compartments (Costill DL, 1976).

More recently, the influence of hydration status on

the movement patterns in football has been

investigated (Edwards AM,, 2007) using the ‘yo-yo’

intermittent recovery test (Krustrup P, 2003;

Bangsbo J, 2008): a reduction of 2.1% or 2.4% in

Mascherini G., Cattozzo A., Petri C., Francini L. and Galanti G..

Application of Bioelectrical Vector Analysis in Professional Soccer Players - BIVA in Sport.

DOI: 10.5220/0004995500840088

In Proceedings of the 2nd International Congress on Sports Sciences Research and Technology Support (icSPORTS-2014), pages 84-88

ISBN: 978-989-758-057-4

 2014 SCITEPRESS (Science and Technology Publications, Lda.)

body mass induced a reductions of 13% and 15%

respectively in ‘yo-yo’ test performance.

Bioelectrical impedance analysis (BIA) is a

property-based method of body composition

specifically detecting soft tissue hydration with a 2–

3% measurement error, which is comparable to

routine laboratory tests (Piccoli A, 2002).

Applications in sport have been primarily for

body composition analysis (Yannakoulia M, 2000),

and recently for assessment of nutritional status and

soft tissue composition in soccer players (Gatterer

H, 2011).

The aims of this study was collect bioelectrical

parameters in soccer players in order to check the

hydration status during an entire season.

2 METHODS

Twenty-five male soccer players were submitted to

BIA measurement during all regular season, but only

eleven athletes (age 22.4±1.8 years, height

181.3±7.7 m) took part in all eight sessions

detection. Absence were due to health reason

(including injuries), soccer players arrived during

the season and the goalkeepers are not included in

this study.

Design: Observational longitudinal prospective

study.

A professional football team taking part at Italian

fourth soccer division begins the season in July.

After having received oral consent to carry out the

evaluations, at the first training session (T1) were

performs anthropometrics and bioelectrical analysis.

Bioimpedance parameters for each players were

recorded in the morning, at rest condition, without

physical activity in the previous 12 h and following

the standard tetrapolar method (BIA 101 Sport

Edition, Akern, Florence, Italy). To detect any

difference in bioelectrical and hydration values of

lean body mass during the season bio impedance

analysis were done three weeks after the first

evaluation (T2) and then every forty days always in

Wednesday morning: total assessment were eight in

all season (T3-T8).

Body impedance is generated in soft tissues as an

opposition to the flow of an injected alternate

current and is measured from skin electrodes that are

placed on hand and foot (whole body analysis). The

resistance (Rz) is the opposition to the flow of an

injected alternating current, at any current

frequency, through intra and extracellular ionic

solutions, while reactance (Xc) is the dielectric or

capacitative component of cell membranes and

organelles, and tissue interfaces.

Data analysis were perform by software

Bodygram PRO 3.0 and detect with a convectional

analysis (BIA) and Vector analysis (BIVA).

Conventional BIA is based on electric models

supporting quantitative estimates of body

compartments through regression equations which

are not valid in individuals with altered hydration.

Bioelectrical impedance vector analysis (BIVA) is

based on patterns of the resistance-reactance graph

(Rz - Xc graph) relating body impedance to body

hydration without equations (Kyle UG, 2004). A

simple algorithm with few operational rules has been

derived for interpreting impedance vector position

and migration on the Rz - Xc graph at the bedside in

any clinical condition. Impedance (Z vector, ohm) is

represented with a point in the Rz - Xc plane which

is a combination of Rz and Xc. Vector normalization

by the subject’s height (Z/H, in Ω/m) controls for the

different conductor length (Codognotto M, 2008).

This new methods is mainly used in clinical

conditions, few studies are now present in literature

(Jaffrin MY, 2009).

Data from conventional analysis were:

free fat mass (FFM), fat mass (FM), total water

(TBW), extracellular water (ECW), intracellular

water (ICW), body cellular mass (BCM), extra

cellular mass (ECM).

For vector analysis the bioelectrical parameters

resistance, reactance and phase angle (PA) lead to

the development of resistance-reactance graph.

For each parameter recorded in the eight sessions

was performed statistical analysis with ANOVA

Test.

3 RESULTS

The data recorded by conventional BIA processing

were report in table 1and didn’t show any statistical

differences both in weight, hydration and cellular

masses.

Bio Impedance Vector Analysis shows a high

significance in Anova test for the values of Xc and

PA (table 2), but no difference in Rz among the

eight measurements.

Figures 1 shown the vector analysis of the eight

assessment during the regular season: sample group

it is positioned for whole regular season in athlete’s

area characterized by a state of lower general

hydration and a higher cellular mass respect the

general population.

The position of sample group in vector graph,

however, varies from July to May and it is possible

ApplicationofBioelectricalVectorAnalysisinProfessionalSoccerPlayers-BIVAinSport

Table 1: Conventional BIA results.

Weight (kg) FFM (kg) FM (kg) TBW (L) ECW (L) ICW (L) BCM (kg) ECM (kg)

T1 74.9±6.4 62.2±5.9 12.7±2.4 45.5±4.3 18.0±2.0 27.5±3.0 37.6±3.5 24.5±2.9

T2 75.6±6.7 63.5±6.2 12.0±2.1 46.5±4.5 18.6±1.9 27.9±3.1 38.1±3.8 25.3±2.6

T3 75.0±6.6 63.0±6.1 12.0±2.1 46.1±4.5 18.5±2.0 27.6±31 37.7±3.7 25.2±2.8

T4 75.3±6.5 62.2±6.5 13.0±2.5 45.5±4.7 17.4±2.4 28.1±2.9 38.6±4.0 23.5±3.5

T5 76.4±6.5 62.1±6.1 14.2±2.2 45.5±4.4 17.6±2.2 27.9±3.0 38.3±3.5 23.8±3.1

T6 76.3±6.5 62.8±6.4 13.5±2.2 45.9±4.7 17.2±2.2 28.7±3.0 39.5±4.1 23.2±3.1

T7 76.1±6.2 62.1±5.9 13.9±2.0 45.5±4.3 17.4±2.2 28.0±2.8 38.5±3.6 23.6±3.2

T8 75.9±6.7 63.8±6.5 12.2±2.1 46.7±4.7 17.7±2.1 28.9±3.1 39.8±4.2 23.9±3.1

Anova NS NS NS NS NS NS NS NS

Legend: FFM = Free Fat Mass, FM = Fat Mass, TBW = Total Body Water, ECW = Extra Cellular Water, ICW = Intra Cellular Water.

Table 2 BIVA results.

Rz (ohm) Xc (ohm) PA (°)

T1 496.4±37.9 65.8±7.4 7.5±0.5

T2 481.1±36.6 62.5±5.0 7.4±0.3

T3 485.5±32.6 62.9±5.1 7.3±0.3

T4 498.0±44.3 70.0±10.3 8.0±0.8

T5 502.2±37.4 69.1±7.5 7.8±0.5

T6 494.0±42.2 71.3±9.0 8.2±0.7

T7 501.1±40.9 70.1±8.5 7.9±0.8

T8 479.9±38.5 68.0±7.9 8.0±0.6

Anova NS <0.01 <0.001

Figure 1: Bia Vector with res.istance-reactance graph of soccer players.

to identify four major groups T1, T2-T3, T4-T7, T8.

From the first detection (T1) is present in an initial

rehydration phase (T2-T3).

In T3-T7 vector analysis shows a loss of fluids with

slight increase in cell mass. Last assessment T8

shows an overall increase in body water.

4 DISCUSSION

The usefulness of body impedance measurement in

sports derives from an immediate availability as a

noninvasive, inexpensive and transportable test that

icSPORTS2014-InternationalCongressonSportSciencesResearchandTechnologySupport

transforms electrical properties of tissues into body

composition information (Kyle UG, 2004).

Acute changes in body mass over a short time

period can frequently be assumed to be a result of

body water loss or gain (Lentner C, 1981; Maughan

RJ, 2007) and therefore changes in body mass can

be used to quantify water gain or loss.

A regular season in professional soccer is 10

months length, during this time the footballers has in

average 250 training session and 45 official matches:

during this time numerous physiological changes

occurs. Footballers are in young age and the

parameters of body composition and hydration are

generally regular, therefore small variations in

conventional analysis (BIA) were reported.

Bio Impedance Vector Analysis (BIVA) in this

particular sports population may give specific

information for physiological changes for training

dues.

In July, at the first analysis (T1), players has a

good condition but a lower level of training, there

were considered the baseline of bioelectrical values.

In August (T2) and in September (T3) the

temperature and the training load were high: Rz, Xc

and PA reached the minimum values with statistical

differences for Xc and PA, we can assume a

redistribution of body water as a first response to

training loads.

Vector parameters from T4 to T7 are stabilized

and do not differ among themselves, during this

phase physical effort of athletes can be considered

stable.

In last evaluation (T8) the increase in body water

can be attributed to a decrease in training load by the

end of the official games.

In conclusion the shift of sample group within

the Rz - Xc graph during the eight assessments

shows how the body of athletes, through training,

initially (T2-T3) undergoes an increase and

redistribution of body water (in favor of the extra-

cellular compartment), then the cellular mass (lean

body mass) increase simultaneously with a reduction

in body water (T4-T8).

A regular Bio Impedance Analysis for

physiological assessment in athletes is advisable to

follow the adaptations to training loads. In particular

during the initial period of regular season when the

high level of physical effort is required: during this

period water loss through the sweat will be

prevented and replenished during and after the single

training sessions.

Also to be considered both the increase in the

summer period and the not change during the season

in total body water in order to plan the training.

Therefore medical and technical staff will have

information to avoid a possible occurrence of

overreaching or overtraining syndrome.

5 CONCLUSIONS

Conventional BIA analysis does not appear

sensitivity to detect athletes adaptations:

bioelectrical values as Resistance, Reactance, Phase

Angle and therefore a Bio Impedance Vector

Analysis (BIVA) is proved more sensitive to

physiological adaptation in sports subjects.

Future research is needed to determine which are

the most stressed muscle groups of the lower limb

from training in football

ACKNOWLEDGEMENTS

The authors did not receive any financial support for

doing this analysis and presenting it in this report.

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