Medical Hydrology and Balneology: Environmental Aspects

Changes in diuresis after rehydration with mineral
waters of different mineralization after a
sesión of submaximal exercice in a warm
atmosphere
Meijide R (1) , Agrasar C (1) , Santiago M (1) , Saavedra M (2) , Barral R (2)
(1) Departament of Medicine, University of A Coruña, A Coruña, Spain
(2) Departament of Physical Education and Sport, University of A Coruña, A Coruña, Spain
rmf@udc.es
Introduction and Objectives
The exercise involves fluid and electrolyte loss that is increased in warm and
humid conditions. Athletes have to recover those losses through proper hydration to
help them compete or develop subsequent training sessions with optimal performance.
Studies suggest that hydration with sodium bicarbonate waters with high
mineralization reduce dieresis and increase the hydration of the body after anaerobic
exercise decreasing the time of fatigue. Magma mineral water® (Spain) is an
alkaline bicarbonate water, characterized by a relatively high content of bicarbonate,
sodium, carbon dioxide, silicon in addition to calcium, magnesium, lithium and
fluoride ions. The aim of this study is to determine the changes in hydration and
diuresis after administration of two mineral waters, a weak and a strong mineralization
(WMW and SMW) after a 90 minutes submaximal exercise with high temperature
and humidity
Materials and Methods
We performed a crossover trial with 8 subjects, cyclists with high degree of
training, which was previously done ergospirometry to determine maximal oxygen
consumption (VO2 max). 90 minutes underwent cycle ergometer exercise, the first
30 minutes at 70% VO2 max. The next 30 minutes at 60% and the last 30 minutes
at 50%, temperature 28º C and a humidity of 50%. Following the exercise were
given an amount of a type of drink 150% of lost weight (initial weight-final
weight): 1/3 in the first 30 minutes and 1/6 at intervals of 30 minutes, with a rehydration
along 5 hours. After that period were allowed to drink ad libitum. The test
was repeated under the same conditions with the second type of drinking water for
two weeks.
The variables studied were initial and final weight, fluid intake during the five
hours of recovery and then at home, dieresis during the five hours of recovery and
subsequent dieresis of each athlete at home (at 12 hours). Statistical analysis: Quan-
Balnea
2012, núm. 6, 218-219
218
ISBN: 978-84-669-1887-0
978-84-669-3482-4