Changes in diuresis after rehydration with mineral waters of different mineralization after a sesion of submaximal exercice in warm atmosphere Drs. Rosa Meijide-Faílde Carlos Agrasar-Cruz Miguel Santiago-Alonso Miguel Saavedra-García Ramón Barral-Lavandeira Department of Medicine Faculty of Physical Education and Sports University of Coruna Spain
Hydration and Physical Performance The exercice involves fluid and electrolyte loss that is increased in warm an humid conditions Athletes have to recover those losses through proper hydration to help them compete or develop subsequent training sessions with optimal performance. Casa DJ, Clarkson PM, Roberts WO: American College of Sports Medicine Roundtable on Hydration and Physical Activity: Consensus Statements. Curr Sports Med Rep, 2005. 4:115 127. Company Logo
Hydration and Physical Performance - Dehydration of more than 2% of body mass can compromise physiological function and impair exercise performance capacity - Greater levels of dehydration exacerbate the negative responses - Decrease in VO2 max - Exercise time to fatigue - Alter the homeostasis Water losses (measured in body weight %) 10 9 8 7 6 5 4 3 2 1 Alteration of thermoregulation capacity 2% 3% 4.6% >6% Endurance decrease Muscular strengh and endurance decrease. True cramps in warm wheather True hard cramps, heat exhaustion, heat stroke, coma, death Dehydration effects on physical performance - Shirrefs SM. Scand J Med Sci Sports 2010: 20 (Suppl. 3): 90 94 Company Logo
Hydration and Physical Performance Many studies have confirmed that plain water is not the best solution to be consumed after exercise to replace the water lost as sweat Tap water for hydration leads to hemodilution: the decrease in plasma osmolality and the concentration of sodium and The increase of diuresis The fluid excreted in urine counteracts rehydration Rehydration after exercise can only be achieved if sweat electrolyte losses as well as water are replaced. Gonzales-Alonso J, Heaps CL, Coyle EF. Int J Sports Med 1992 R J Maughan, J B Leiper, S M Shirreffs. BrJ Spors Med 1997
Hydration and Physical Performance To replace losses in the sweat, the drinks should contain moderately high levels of sodium (perhaps as much as 50-60 mmol/l) and possibly also some potassium. Most commonly consumed soft drinks contain virtually no sodium and these drinks are therefore unsuitable when the need for rehydration is crucial. Some studies suggest that hydration with sodium bicarbonate waters with high mineralization reduce diuresis and increase the hydration of the body after aerobic exercise decreasing the time of fatigue. Heil DP. J Int Soc Sports Nut 2009
Bicarbonate-alkaline mineral water Magma of Cabreiroá (Spain) The mineral water Magma of Cabreiroá (Spain) is an alkaline bicarbonate water Characterized by a relatively high content of bicarbonate, sodium, carbon dioxide, silicon ions besides calcium, potasium, magnesium, lithium and fluoride. Dry residue Magma Cabreiroa 1.518 mg/l CO 3 H 1.616.5 Cl 26.0 F 4.8 Ca 21.7 Mg 12.6 Na 545.7 Li 2.9 K 50.5 SiO 2 60.4 CO2 1.200
Objective The aim of this study is to determine the changes in hydration and diuresis after administration of two mineral waters, with a weak and a strong mineralization (Magma of Cabreiroa) after a 90 minutes submaximal exercise with high temperature and humidity in professional cyclists
Subject and methods Crossover trial 8 males cyclists with a high degree of training Ergoespirometry previously to determine maximal oxygen consumption (VO2 max) They did 90 minutes of 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%
Subject and methods Following the exercise they were given an amount of a type of drink water 150% of lost weight (initial weight-final weight): A 1/3 in the first 30 minutes and A 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 in two weeks Dry Residue mg/l Magma Cabreiroa Weak mineral 1.518 96 CO 3 H 1.616.5 22.8 Cl 26.0 8 F 4.8 - Ca 21.7 3.6 Mg 12.6 0.4 Na 545.7 6.1 Li 2.9 - K 50.5 1.1 SiO 2 60.4 15 CO2 1.200 10 Company Logo
Subject and methods The variables studied were: initial and final weight, fluid intake during the five hours of recovery and then at home, diuresis during the five hours of recovery and subsequent diuresis of each athlete at home (for 12 hours). Company Logo
Statistical analysis A descriptive study of the variables included in the study Qualitative variables are expressed as absolute values and the estimated percentage of 95% confidence interval. Quantitative variables were expressed as mean ± SD. The comparison of means test was performed with the Student t-test or Mann-Whitney U as appropriate after testing for normality with the Kolmogorov-Smirnov test
Main results The baseline characteristics of athletes Variables Mean Age 24.00±6.74 Heigh 178.2±4.12 Baseline weight 67.76±9.38 BMI 21.28±2.41 Fat mass 7.74±2.4 Percentage fat mass 11.09±1.78 Muscle mass 31.98±5.05 Percentaje of muscle mass 47.00±1.17
Main results Magma Cabreiroa Mean ± SD Weak Mineral Mean ± SD p Initial Weigth 68.7 ± 9.9 67.7 ± 9.5 0.988 Final Weigth 65.6 ± 9.5 65.7 ± 9.1 0.987 Percentage of dehydration 3.23 ± 0.45 3.01 ± 0.39 0.327 WATER INTAKE Water Intake Water Intake 60 Water Intake 120 Water Intake 150 Water Intake 300 Total Water Intake 1651.5 ± 405.2 1556.25 0.621 1101 ± 27.02 1037.5± 23.1 0.621 550.63 ± 13.5 519± 11.6 0.623 3303.13 ± 810.5 3112.5± 693.2 0.621 4506.25 ± 1045.1 4171.8 ± 647.1 0.619 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 1st hour intake 2nd hour intake 3rd hour intake High Min Water 5th hour intake Intake at home Low Min Water Overall intake Company Logo
Main results of diuresis Total (ml) Magma de Cabreiroá ml Weak Min Water ml 1ª hour 68 180 <0,006 2ª hour 190 424 <0,003 3ª hour 409 850 <0,001 4ª hour 837 1306 <0,001 p 3000 2500 2000 1500 1000 500 5ª hour 1321 1734 <0,002 0 60 120 180 240 300 Domic Tot AMF AMD The rehydration is much more effective when athletes are hydrated with Magma water
Conclusions For hydration in the first five hours after exercise it is better to drink heavily mineralized water (MAGMA Cabreiroá) than a low mineral water, which is the one usually used to rehydrate athletes. The decrease of urine output, leads to a greater water retention inside the body, and provides better conditions allowing the recovery of the athlete to perform a new training session or competition. Acknowledgements to Cyclists, To Faculty of Physical Education and Sports University of Coruna and to Cabreiroá mineral waters