Variation in measurement results of extracellulair fluid of arms under different measurement conditions using the L-Dex U400

The L-Dex U400 bio-impedance measuring device which is applied to determin
extracellulair fluidr in an extremity. The reliability of the L-Dex U400 under
different measurmen conditions, for example different measuring sessions or
different observers has not been investigated. Additionally the amount of
variation in measurement results due to different conditions has not been
determined. Differences in outcomes in patients suffering form early lymph
edema (extracellular fluid) cannot be interpreted correctly. Differences could
caused by changes in the amount of extracellular fluid, but also by lack of
precision in the L-Dex U400. Therefore we want to determine first in healthy
subjects what the variation in measurement results obtained with the L-Dex U400
is under different conditions.

The aim of the study is to determine the variotion in measurments of
extracellular fluid of the arm using the L-Dex U400 during different
measurement conditions in healthy subjects.

The study has a repeated measuremt design.
Measurments (in total 12) wil be performed: a baseline measurement, after a
short rest (10 min.), drinking coffee (200ml), change electrodes (another
observer) and after moderate exercise (30 minute cycling on a home trainer,50
Watts, 50-60 RPM) and after a final short rest period. In the next measurement
session, a week later, the same measurement protocol wil be repeated.

The burden to participate is low. The participants have to cycle for 30
minutes 50 Watts, corresponding to cycling to school and/ or work. There are no
risks associated with participation.