Submitted: International Journal Of Sport Nutrition And Exercise Metabolism.
Hottenrott, K., Lutzke, E., Mücke, M., Zurleit, A.
Institute for Performance Diagnostics and Health Promotion at the Martin Luther University of Halle-Wittenberg
Effects of alkaline glacier versus mineral water on endurance performance in trained cyclists
Background and objective: Water provides a performance-limiting factor regarding performance during exercise. Besides quantity and time of consuming water, its quality and composition is also important. The essential functions of water are in the continuous exchange of construction and degradation products of individual metabolic processes as well as in the transport capacity of minerals and nutrients and trace elements. In addition, athletes benefit from alkaline supplementation with hydrogen carbonate. It has been shown that alkaline supplementation before exercise can prevent a decrease in blood HCO3- during high intensity exercise (Pouzash et al., 2012).
So far the hydrogen carbonate buffering of alkaline water for serval days has not been tested for performance-influencing effects in defined endurance exercise. Consequently, the aim of the study was to evaluate the influence of alkaline glacier water and commercially available mineral water on aerobic and anaerobic capacity.
Methodology: The quasi-experimental study involved 7 women cyclists and 11 men cyclists with a mean age of 26.4 ± 4.8 years, a body weight of 69.8 ± 8.4 kg and a BMI of 23.1 ± 2, 6 kg/. The physical activity of the subjects was 7.2 ± 2.6 hours per week. In max tests the men reached an oxygen uptake of 56.9 ± 7.8 ml kg and the women of 42.4 ± 2.4 ml kg.
Study Design: A controlled, easily blinded cross-over design was chosen. After determining the max, the subjects were randomly separated in two groups. In intervals of 7 days, the cyclists completed and aerobic time-to-exhaustion test on a high- performance ergometer at a power of 80% of max and then, after a 20 minutes recovery period, an anaerobic 75-sec cycling test at 90 U / min. Three days before the test the athletes consumed at least 3 litres of mineral water or alkaline glaciers every day. On the test day, the athletes drank one hour before starting the test a litre of mineral or alkaline glacier water and a pint between the two endurance tests. The diet in the days before the test was controlled and standardized with respect to the liquid supply. Statistical analysis was performed using SPSS 20.0. The significance level was set to p ≤ 0.05.
Results: The cyclists in the intervention with alkaline glacier water scored in the time-to-exhaustion test with 47.4 ± 6.7 min compared to 43.4 ± 9.3 a (<.01 p) min a highly significantly longer travel time than the cyclists in the intervention with mineral water. The difference is absolut four minutes or relative 8.4% (Figure 1). After the end of the test, the oxygen uptake in the intervention with alkaline glacier water is significantly higher (p = 0.027) than in the intervention with mineral water (46.8 ml min kg versus 44.9 ml kg).
To determine the anaerobic capacity the average pedalling was arrived at an isokinetic 75-second Cycling test. Subjects in the intervention with the alkaline glacier water achieved an output of 446.6 ± 164.9 watts and subjects with mineral water 410.7 ± 128.8 watts (Figure 1). This difference of 36.6 watts or 8.2% is highly significant (p <.01).
Discussion: The oxygen-binding capacity of the blood is dependent on the pH value. At higher blood pH the oxygen binding properties of the blood are better. During intense physical stress the blood pH can fall below 7.0 (Maassen et al., 1999). Various buffer systems can change the pH value influence (Pilegaard et al., 1999). Milieu shifts are an important limiting factor in endurance performance (Heil, et al., 2012). The improved buffering capacity and oxygen-binding capacity can have contributed to the improved performance in the cycling test in the intervention with alkaline glacier water among other factors. It has been shown that induced alkalosis can improve performance by possible increasing the blood buffer capacity (Nielsen et al., 2002). Accordingly, the amount of blood pH decrease during intensive exercise could be modified by alkaline water consumption. The buffering capacity of the blood has a direct influence on the acid-base balance and thus on the endurance capacity.
Conclusion: Compared to mineral water alkaline glacier natural water showed to improve aerobic and anaerobic capacity by an intake for several days. This study highlighted that a performance enhancing effect can be achieved with a natural product from the glaciers.
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Nielsen HB, Bredmose PP, Stromstad M, Volianitis S, Quistorff B, Secher NH. (2002). Bicarbonate attenuates arterial desaturation during maximal exercise in humans. J Appl Physiology. 93:724-731.
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Pouzash, R., Azarbayjani, M., Pouzesh, J., Azali, K., & Fatolahi, H. (2012). The Effect of Sodium Bicarbonate Supplement on Lactic Acid, Ammonia and the Performance of 400 Meters Male Runners. Baltic Journal of Health and Physical Activity, 4 (2) 84-90.
Prof. Dr. Kuno Hottenrott, Institute for Performance Diagnostics and Health Promotion at the Martin Luther University of Halle-Wittenberg, Email: email@example.com