Sporting Nutrition Research Paper Peer Reviewed Journal Research Paper Example
Evaluation of Fluids in Commercial Sports Drinks
Athletes and sport personnel involved in heavy exercise are limited by two major factors, dehydration and carbohydrate depletion. In this regard the sportspersons need to replenish the body fluids with beverages containing carbohydrates. This however causes a challenge since the optimal formulation of sport rinks has not been fully determined. Over many years experts were confused over how exactly to handle such situations.
It was commonly adapted that consuming beverages that contained over 2.5% carbohydrate will not do well in achieving fluid replenishment since is decreases gastric emptying rate. This will then increase dehydration, heat illness and stomach upsets. Secondly malt dextrin, glucose polymer , solutions have more advantages to the athletes since they offer more carbohydrates and fluid replenishment. It was assumed that these solutions dissolve much faster into the body fluids and have lower osmolality. However recent studies suggest otherwise.
When carrying out tests on gastric emptying caution must be taken. First measurement of gastric emptying is difficult to attain accuracy and positioning of the naso-gatstric tubes causes the subject of experiment too much pain and may cause alters in gastric emptying rates. Further the studies did not focus on intestinal absorption of intestinal and endogenous fluids. The process therefore only reflects one part of the fluid uptake process.
Generally, the overall rate of fluid and carbohydrate absorption is determined by both the rates of intestinal absorption and gastric emptying. This research developed a new approach to measuring availability of water in ingested drinks or beverages for dilution into boy fluids. This method is much more qualitatively useful since it is based on both gastric emptying and intestinal absorption. This research came up with the following conclusions:
1. Beverages whose absorption rates are faster or slower than water can be compared by simply measuring how fast deuterium oxide (D2O) accumulates from this beverages.
2. Deuterium oxide (D2O) accumulation in plasma ingested during rest and during exercise is similar for labeled water and 6% and above carbohydrate electrolyte beverages.
Besides this new and exciting findings there are is no data available on existence of sports fluids containing between 6 to 10 % carbohydrates in the form of either glucose polymers or simple sugars. This is saddening despite the advantages associated with the combination.
The purpose of this study was to compare the how different levels of carbohydrate mixtures accumulate water profiles in the plasma. The study tested the accumulation of (D2O) water profiles under resting conditions in four different carbohydrate containing sugars.
Materials and Method
This study employed 8 young lads, especially college aged. They were informed of the benefits of the research as well as the health dangers involved in the study. D2O accumulation would be tested after ingesting any of the four beverages and water. The ingested beverages contained 6% glucose-fructose mix (30 g glucose/L, 30 g fructose/L), 6% malto-dextrin (6% M, 60 g malto-dextrin/L),10% glucose + fructose mix (50 g glucose/L, 50 g fructose/L), and 8% glucose + fructose mix (40 g glucose/L, 40 g fructose/L). Except for distilled water, the other beverages contain 20 ml sodium/L and 3 ml potassium/L. The beverages were flavored to appear indistinguishable to the experiment subjects.
The subjects reported to the lab on five different occasions each separated by a week. It was essential for the subjects to conduct the experiment on empty stomachs. A twelve hour break from food was instructed before the experiment. 10ml blood samples were drawn from the subject and placed in a sealed tube containing potassium EDTA which is an anticoagulant. The subjects consume 275 milliliters of the best prepared beverage within about 60seconds. To serve as a marker of fluid uptake the mixtures contained 20m of purified atom% D2O. Blood samples were taken immediately before the intake and after 10, 20, 30, 40, 60, 90,120 and 180 minutes after intake. During this period subjects could only rest.
Concentration of plasma D2O increased highly between the first forty minutes reaching a peak of 450mg/L. There are no significant differences in the plasma D2O concentration in the ingested beverages. On the other hand plasma glucose concentration increased rapidly immediately after the ingestion of the carbohydrates. By 20 minutes the carbohydrate-electrolyte level peaked at 8%GF and 30minutes at 6% GF. Plasma glucose levels were high with injection of carbohydrate-electrolyte drinks than when water was used. No much difference was recorded in the group after 90minutes. The stands remained the same throughout the remainder of the 180minutes.
Further, insulin concentration increases significantly within the first 20-30minutes after intake of the carbohydrate-electrolyte drinks. The tiniest insulin response had 6% GF and resulted in quite low insulin concentration when compared with the other carbohydrate-electrolytic drinks. Although its presence was quite high at 30 minutes with 6%M, 8%GF and 10% GF the integrated insulin response had no significant difference between the different consumed carbohydrate- electrolyte beverages. The plasma insulin returned to normal after 60 minutes and did not change for the remaining part of the 180minutes.
This study was trying to measure and compare plasma accumulation of D2O after consumption of different types of carbohydrates in different forms of concentration. It is important to note that the purpose of this experiment was to help athletes during exercise in finding a perfect mix of reducing dehydration and carbohydrate depletion. This might be an important solution for athletes in the various fields of competition.
This concept has been used has been used to make comparisons in fluid availability of a wide range of beverages. However, it has never been used to draw comparisons in composition of drinks used in commercial sports.
The rate at which consumed food joins the vascular system is not an independent function. It takes into account how fast the contents will be absorbed from the intestine and how fast they will be emptied from the stomach. This method of using D2O is much simpler than conventional methods since it allows for an easy tracking of relative difference in the absorption of the fluid and fluid availability after injection.
The results in this experiment show that the fluids are availed for dilution and intake into body fluids similar rates after drinking of the beverages containing equal or less than 10% carbohydrates. This experiment is the first of its kind and the results are very different from previous research about the topic. Earlier experiments based their judgment on gastric emptying only and forgot to incorporate rate on absorption.
In their experiment Costil and Saltin identified those beverages containing concentrations of simple sugars emptied slower than water. Coyle also confirmed these results in their experiment concluding that a commercial sport drink for athletes containing less than 4.5% of glucose and fructose emptied faster from the stomach than water placebo.
On the other hand Foster in his experiment concluded that those solutions that had a high amount of carbohydrate took longer to be absorbed but a 5% malto-dextrin mixture emptied quicker than an equal concentration of glucose. From these previous results they drew conclusions that simple sugar solutions containing more than 2.5% would inhibit absorption and should not be recommended to any athlete for during a normal exercise. They also thought that fluids containing malto- dextrins are much better at replenishing carbohydrates and body fluids than those containing simple sugars. This they said was due to lower osmolality that led to faster gastric empting.
The optimum contents of a preferred beverage for athletes and sports people are still under argument. However, form this experiment several productive remarks that can help in determining optimum drink levels can be drawn. It is evident that a carbohydrate- electrolyte beverage that contains between 2.5 % and 10% of carbohydrate may not necessarily enter the vascular system slower than water. If this is true, scientifically proven it means that the carbohydrates will not compromise replenishment of body fluids for athletes in exercise. Further, use of malto- dextrins in sport drinks do not provide any extra benefit as seen is this experiment. This is because solutions with moderate amounts of concentration of malto-dextrins and those solutions containing simple sugars are easily made available for absorption and dilution into body fluids ate more less equal rates. The results of this experiment may be the turning point for sports drinks manufacturers to consider. Further researcher should also proceed with their research having read this as a literature review.
Coombes, J. S., & Hamilton, K. L. (2000). The Effectiveness of Commercially Available Sports Drinks. Journal of the American Medical Association.
Kerksick, C., Harvey, T., Stout, J., Campbell, B., Wilborn, C., Kreider, R., Antonio, J. (2008). International Society of Sports Nutrition position stand: Nutrient timing. Journal of The International Society of Sports Nutrition. doi:10.1186/1550-2783-5-17