Heat Illnesses and Carbohydrate Drinks

July 2, 2011

This is another research paper I wrote for my undergrad Exercise Physiology class…

There are many ways athletes prepare for competition whether it is in the weight room, on the field, or even sleeping. One common regimen is overlooked and that is proper hydration. Some of it is due to the lack of knowledge while some are taught some very interesting remedies. It is the hope of the author to give some insight into what the body needs for proper hydration during activity and how the body uses the fluids provided.

During exercise, many reactions occur in the body that allow for movement. Without multiple chemical reactions, there would be no energy, muscle fibers would not contract or relax, and no movement would occur. This movement is going to cause the body temperature to increase. With this increase, the body naturally is going to attempt to cool itself down through sweating. Sweating is normally considered to be a good thing because of the cooling effect, but there are side effects to sweating including the loss of water. Losing more than approximately 3% of one’s body weight in water through sweat can lead to dehydration and leave the athlete susceptible to heat illnesses (Casa et al, 2000). Even with the negative potential, sweating is important so that the body does not overheat causing a disruption in various systems throwing off the equilibrium of body fluids as well as potentially increasing pH, blood pressure, and body temperature (Cooper et al, 2006).

Research is not definitive as to the main cause for heat illnesses. The name itself gives one reason, but one can experience these so-called “heat illnesses” even in cold weather. Cooper et al(2006) found in their study that 88 percent of i heat illnesses occurred in August while the other 12 percent occurred in September. This can be attributed to the environmental temperature, but also the athletes’ acclimatization and the relative intensity of the practice at that time in the season both must be considered. Jung et al (2005) suggests that heat cramps are caused by the lack of fluids, electrolytes, and heat but their study shows that these are not absolutes after they had more participants cramp during a trial where the participants were given water and carbohydrates than in a trial where the participants were not given any water or carbohydrates (Jung et al, 2005). This makes one wonder if athletes should be provided with beverages such as Gatorade or Powerade or if the athletes would be better without these products.

This study has results that would appear to question whether these carbohydrate beverages should be given or not, but looking deeper would show that while there were more participants cramping with the carbohydrates, the time it took was significantly longer. That said, it appears the fluids may not influence the cramping, but the carbohydrates in the drink appear to delay the onset of heat cramps (Jung et al, 2005). One thing to remember with this specific research and the incidences of cramping is that these participants were pushed extremely hard nearly until cramping occurred. In normal activity even at a high intensity, it is not expected to continually do high-risk activity for cramping for such a long duration. Electrolytes lost through sweat are said to average as high as 2300 mg×L for sodium and 160 mg×L for potassium (Jung et al, 2005).

To combat the losses of these electrolytes, the National Athletic Trainers Association (NATA) have come out with a position statement with regards to fluid replacement for athletes. There is a recommendation for frequent fluid intake before, during, and after practice and competition. If it is decided to consume a sports drink, the NATA recommends it be a 6% CHO concentration. If that concentration is much higher, it is believed that while the body will process the fluid, there will be a slower emptying of the stomach which could potentially lead to other illnesses. Also, during times of extreme physical exertion it may be beneficial to add small amounts of salt to fluids to help stimulate thirst and decrease the risk of hyponatremia (Casa et al, 2000).

Research shows that there are definitely benefits to providing carbohydrate beverages for athletes during intense workouts even though there is the risk of potential cramping still. The body has to have minerals such as sodium and potassium in order to function and with an imbalance cramping will take place. More research is definitely needed in order to better understand the requirements of athletes as well as finding out more about why heat illnesses occur. Obtaining more information with regards to this subject could not only enhance performance, but would be a life-saver.


Casa, Douglas J., Armstrong, Lawrence E., Hillman, Susan K., Montain, Scott J., Reiff, Ralph V., Rich, Brent S.E., Roberts, William O., & Stone, Jennifer A. (2000). National athletic trainers’ association position statement: Fluid replacement for athletes. Journal of Athletic Training. 35 (2), 212-224.

Cooper, Earl R., Ferrara, Michael S., & Broglio, Steven P. (2006). Exertional heat illness and environmental conditions during a single football season in the southeast. Journal of Athletic Training. 41(3), 332-336.

Jung, Alan P., Bishop, Phillip A., Al-Nawwas, Ali, & Dale, R. Barry (2005). Influence of hydration and electrolyte supplementation on incidence and time to onset of exercise-associated muscle cramps. Journal of Athletic Training, 40 (2), 71-75.


3 Responses to “Heat Illnesses and Carbohydrate Drinks”

  1. TNT Man Says:

    Was there a drink that had all the electrolytes but with out the Carbs? Or – is sugar a necessary component that must be replaced?

    TNT Man

  2. Much of this research was conducted on those individuals who must have those carbs or they would also struggle with energy levels. Athletes and especially endurance athletes must have those carbs. I’m actually looking at a bottle of Powerade right here and for every 8 ounces there are 21 grams of carbohydrates with 20 of that being sugars. There’s 150mg of sodium and 35mg of potassium in that 8 ounces as well as well as a touch of magnesium and calcium.

    Regular Gatorade has 14 grams of carbohydrates per 8 ounces while having 110mg of sodium and 30mg of potassium.

    Your Gatorade and Powerade items are going to have sugars in them specifically for that reason, but also we have found athletes are more willing to hydrate properly with a sports drink rather than water because of the taste.

    Now these companies have introduced new sports drinks that have much fewer calories while still having electrolytes.

    Gatorade’s G2 still has the same electrolyte content, but only has 5 grams of carbohydrates. Powerade Zero has 100mg of sodium and 25mg of potassium while having ZERO calories in it.

    So yes there are drinks out there for those concerned about the carbohydrate drinks.

    I am not a huge fan of the Powerade Zero myself, but I prefer the G2.

  3. TNT Man Says:

    Since your body is programed to burn fats for energy – and reverts to that after the initial burn off of the glycogen – it would be interesting to design a study that really deals with – can you be an endurance athlete and not rely on carbs for energy?

    Just wondering.

    TNT Man

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