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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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