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Is IT  In You?

Introduction

            You are watching ESPN and there is a Gatorade commercial playing in which you see a football player, whose sweat is purple, hauling in a spectacular catch for a touchdown.  The scene then changes to a basketball player, whose sweat is orange, draining a game-winning, buzzer-beating shot to win the game.  The commercial continues in this fashion and then at the end you see an orange lightning bolt appear behind the slogan, “Is IT in you?”  Perhaps you have seen this very commercial; perhaps you know of a similar commercial; perhaps you are completely lost as to what you just read.  If you watch almost any sporting event, you will likely see a cooler marked with the name of a sports drink and filled with just that.  The most prevalent brand of sports drink is Gatorade, but all of the other brands are basically the same thing.  Sports drinks are, in essence, flavored water that has been packed with carbohydrates and electrolytes, that are designed to replenish the carbohydrates and electrolytes that the body has burned off to use as energy during physical activity.  Carbohydrate-electrolyte (C-E) drinks are very popular among professional and recreational athletes as well as everyday people who simply want to exercise.  Obviously, companies such as Gatorade are going to say that C-E drinks are helpful in keeping the body working at its best so that chances of success are maximized, but is there any truth to these claims?  One should assume so given how prevalent C-E drinks are among those participating in athletics or exercise; however, it is not always best to assume that just because something is popular, that automatically makes it helpful.

 

When is IT worth it?

            There are several examples of clinical studies, case studies, and personal accounts that say that Gatorade – or any C-E replenishment drink, for that matter – is effective in keeping athletes and anyone else who is performing some sort of exercise both hydrated and ready to perform at their very best.  While not every study needs to be considered, there are two notable ones that not only make a case for C-E drinks, but also have the data to back up the claims and warrant a closer look.  The first of these studies was performed in Singapore on members of the Singapore military.

            After being given approval by the Defense Medical and Environmental Research Institute Ethics Committee in Singapore, fourteen male soldiers from the Singapore Armed Forces gave their consent to participate in a study to test the effect of C-E fluids versus water intake.  The conditions of the experiment were that the soldiers had to walk on a treadmill three times for one hour per session.  In order to simulate the heat of the outside air during training, the temperature of the room was held at 35°C and the humidity at 55%.  The assignment of the subjects was done in a randomized crossover fashion in which one group drank just water and the other drank a C-E fluid – which was generally Gatorade – immediately before and during exercise at scheduled times.  The subjects of the study dressed in usual marching attire and were given ammunition, a canteen, and a backpack – all combining for a total of approximately 14 kilograms.  The subjects were required to show up at 7:00 a.m. and have a light breakfast with half a liter of water.  After breakfast, the subjects were moved into the laboratory where they were put through cycles of walking on the treadmill and resting that were designed to simulate actual, long marches.  The only difference between the two groups of soldiers was that, when instructed, one group would drink water while the other group drank some sort of C-E fluid.  Throughout the experiment and also when the experiment was completed, the subjects were analyzed on a variety of things, including but not limited to electrolyte concentrations in the blood, heart rate, respiration, sweat loss, metabolic cost, and exercise intensity.  When the average results from the two groups were compared, it was found that the use of C-E fluids was not any more effective than water throughout the simulated marching workout in maintaining fluid balance, heart rate, internal core temperature, or serum sodium concentration.  However, the use of the C-E fluids did prove better than water at keeping blood glucose levels elevated, suppressing the amount of perceived exertion, and, in turn, increasing the rate of task completion.  What this shows is that when it comes to activities that require a higher (but not extreme) level of physical exertion, C-E drinks are no better or worse at maintaining homeostasis (with the exception of blood glucose levels).  However, the use of a C-E drink in lieu of water can decrease the level of perceived physical exertion.  If one feels as though he or she has exerted less energy, then he or she will be willing and able to not only work harder and longer but will also have a faster recovery time from the activity (Byrne, 2005).

            The second study that demands consideration was conducted at the University of South Carolina.  In this experiment, sixteen male and female subjects were selected to participate in this study which consisted repeatedly of a one-minute cycling sprint followed by three minutes of rest.  While all of the subjects were physically active, none of them were trained in the activity.  The subjects were also divided into two groups.  One group was given an 18% C-E drink approximately 20 minutes prior to the exercise and at 20 minute intervals during the exercise.  The other group was given a flavored placebo drink that they were to drink at the same time as the first group.  The time to fatigue was measured throughout the experiment, and the results that were acquired were striking.  The time to fatigue for the members of the group receiving the C-E drink was, on average, 87.5 minutes, whereas the time to fatigue for the members of the group receiving the flavored placebo was, on average, 59.8 minutes.  This translates to the average total number of one-minute sprints completed by the C-E group being 22, while the average total number of one-minute sprints completed by the placebo group was only 15.  This large disparity between the groups was explained by looking at the type of muscle being used in the experiment and the fluid being consumed.  With cycling sprints, the fast-twitch muscle fibers were the ones that were primarily being used in the experiment.  Fast-twitch muscle fibers are good for quick movements, but deplete their glycogen supply rapidly and are therefore unable to perform for extended periods of time.  While the group taking the placebo was being rehydrated by the water, the members were not getting anything else out of the drink.  On the other hand, the members of the group getting the C-E fluid were being rehydrated and were also being supplied with the carbohydrates and electrolytes that the fast-twitch muscle fibers began to quickly need (Ryan, 1997).  As a result, it makes perfect sense that the group receiving the C-E drink performed considerably better than the group receiving the placebo.  From this study and the aforementioned military study, it is clear that C-E drinks such as Gatorade are effective in improving performance in strenuous activities or exercises.

 

When is IT not worth it?

            When the exercise load is simpler, such as walking, light weightlifting, or sports that are physically less intense (like golf) it is no better to have a C-E drink than it is to have a bottle of water.  Although energy stores are being depleted during these relatively undemanding activities, the rate at which energy is being used is not so great that the body cannot recover quickly.  As such, it is unnecessary to consume some sort of C-E replenishing drink in the place of simple water.  A study performed in 2001 by the National Strength & Conditioning Association proves this very point.

            The study performed by the National Strength & Conditioning Association was designed to analyze the effect (or non-effect) of C-E fluid intake versus water intake during exercise.  The subjects were put into three groups: one group was not given anything to drink during the workout, one group was given water, and one group was given a type of C-E fluid (which was usually Gatorade).  In this experiment, subjects were given a variety of tasks to perform including cycling, roller-blading, walking, running, and stair climbing.  The type of data and the manner in which it was collected for this study was quite similar to the manner in which it was done in the Military experiment that was discussed above (and as such will not be repeated).  In every one of the various trials, the result was that when the level of exercise was low to moderate and the duration was only one hour, the intake of C-E fluids yielded results in every category that were no better or worse than those received from the group ingesting water.  In fact, in one of the trials, it was found that both the water group and the C-E group showed performance levels below those of the group that did not drink anything at all.  This may suggest that when the duration of the workout is brief, there is little need for any type of fluid replacement and that it will only prove inhibitive because of the feeling of fullness that it may cause.  Given that sports drinks such as Gatorade are loaded with electrolytes and carbohydrates that are unhelpful in moderate physical activity with a short duration, it is recommended that water is used as a “refresher” after such a workout.  There is no point to putting extra salts and sugars into the body when they are not needed (Albertson et al, 2001).

 

What are the consequences of drinking Gatorade when not exercising?

            Even worse than drinking a sports drink such as Gatorade after low to moderate exercise is drinking Gatorade when no exercise is performed – when people drink Gatorade simply because they like the taste.  It should seem intuitive that drinking something loaded with salt and sugar is not healthy under normal circumstances, but many people do not consider such things.  Put quite eloquently, “If you were to consume one [20 ounce bottle of Gatorade] every day, instead of water, the annual difference in calories would tally to over 40,000.  If your activity level and other calories were constant, daily intake of Gatorade instead of water could mean a ten pound weight gain in a year” (davidkatzmd.com, 2005).  This is not to say that drinking Gatorade is a bad thing, it just means that consumption of Gatorade needs to be accompanied with exercising to such a degree that constitutes drinking a C-E fluid such as Gatorade in order to replenish the burned salts and sugars.

 

Conclusion

            In summary, there is, in fact, overwhelming evidence that consumption of Gatorade – or any other sports drink, for that matter – during strenuous physical activity is not just helpful, it is advised.  The consumption of Gatorade during strenuous physical activity can lead to increased endurance, delayed perception of exhaustion and fatigue due to increased energy, overall improved performance (resulting from the previous two), and decreased time required for recovery from the activity.  While all of this is good to know and keep in mind when working out, one must also keep in mind that if the level of activity is not very high or if the activity is only being done briefly, the use of Gatorade is not necessary.  In this case, what the body really needs is water replacement more so than C-E replacement, and since Gatorade and water have essentially the same effect in this situation, water is the healthier choice (since it avoids unnecessary extra salts and sugars).  Finally, even though it may be okay to have Gatorade when it is not really needed, especially for those who are not participating in any sort of physical activity, Gatorade is a bad choice for use as simply a “thirst quencher”.  The excess salts and sugars found in Gatorade make it a decidedly unhealthy choice and one should definitely think twice before downing a Gatorade simply because it may taste good or look more appealing than a bottle of water.  However, overall, if taken appropriately, Gatorade, as well as all of the other C-E replacement drinks, most certainly live up to their hype.

 

References

Albertson, L., Bachle, L., Ebersole, K., Eckerson, J., Goodwin, J., & Petzel, D. (2001). “The Effect of Fluid Replacement on Endurance Performance.” Journal of Strength and Conditioning Research. 15(2), 217-224. Retrieved September 20, 2006 from the World Wide Web: http://www.hawaii.edu/hivandaids/Effect%20of%20Fluid%20Replacement%20on%20Endurance%20Performance.pdf

Byrne, Christopher. (2005, August). “Water versus Carbohydrate-Electrolyte Fluid Replacement during Loaded Marching Under Heat Stress.” Military Medicine. 170(8), 715.

(2005, July 31). “Hydrating the Hypo-Active.” Preventative Medicine Column. Retrieved September 20, 2006 from the World Wide Web: http://www.davidkatzmd.com/admin/archives/hydrating%20the%20hypo-active.Times.7-31-05.doc

Ryan, Monique. (1997, October). “Sports drinks: research asks for reevaluation of current recommendations.” Journal of the American Dietetic Association. 97.n10: S197(2). Health Reference Center Academic. Thomson Gale. Vanderbilt University Library. Retrieved September 20, 2006 from the World Wide Web: http://find.galegroup.com/itx/infomark.do?&contentSet=IAC-Documents&type=retrieve&tabID=T002&prodId=HRCA&docId=A20343024&source=gale&srcprod=HRCA&userGroupName=tel_a_vanderbilt&version=1.0