As discussed during this weeks TBL activities, severe dehydration can have detrimental effects on exercise performance. With dehydration comes a decrease in blood plasma volume and an increase in blood viscosity. Increases in heart rate and core body temperature follow as difficulties in thermoregulation become and issue, all of which result in a lower power output by the body. One of the primary ways we can avoid these effects is to not only ensure adequate water intake prior to and during an exercise bout, but also to supplement the water we drink with some table salt so that we have enough sodium in our circulation to retain the water.
Surely there are some other ways we can maintain our peak performance during an exercise bout with hydration alone. For instance, throwing your water bottle in the refrigerator before going on a run or bike ride might seem obvious. Drinking cold water would indeed assist in keeping the core body temperature down as heat is drawn away from the body to the water, which in itself possesses a high heat capacity. This, in fact, is an effective technique in delaying increases in core body temperature during exercise, as determined by Lafata et. al in what is oddly one of the few studies that looks at the effects of drinking cold water on exercise performance (this is NOT to say, however, that drinking cold water alone will significantly increase your peak performance from baseline, as determined by the exercise tests performed by the subjects in the experimental trials).
Another factor that we should consider is the amount of sugar/carbohydrates that are present in the sports drinks that some individuals choose to consume in place of water. With brands like Gatorade and Accelerade pushing products with an "ideal" carbohydrate content, it would make sense to have a hydrating formula that would replenish your glucose availability during a particularly difficult training session or competition. After all, "bonking," or rather fatigue as a result of glycogen depletion, is a major concern for endurance athletes. However, consider the following experiement performed by Dr. Allen Lim of Skratch Labs:
https://www.youtube.com/watch?v=8NNRpxBTpk8&t=153s
As displayed in this experiment, the solutions with greater concentrations of sugar acted like hypertonic solutions that pulled fluids out of the partially dissolved eggs, which mimic the permeability of the human intestinal linining to water. The take away of this experiment is that sports drinks that contain high concentrations of sugar and that are supposedly meant to replenish the body's sugar stores as an energy source during physical activity are actually pulling fluids OUT of your system, dehydrating you, and interfering with your body's ability to thermoregulate itself.
So where do we go from here? Whatever it is that you choose to drink before or during an exercise bout, do your best to avoid the sugary stuff. If maximizing your glycogen stores is something that concerns you, make sure to take care of that BEFORE an exercise bout by eating enough and properly. However, if prioritizing your body's need to thermoregulate itself is more important to you, then simply cool down your water after supplementing it with some salt. It's all you need, really.
Lafata, D., Carlson-Phillips, A., Sims, S.T., Russell, E.M. (2012, Sept. 19). The effect of a cold beverage during an exercise session combining both strength and energy systems development training on core temperature and markers of performance. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22992430
[Skratch Labs]. (2012, May 3). Keeping it real with hydration science and practice to make you faster [Video file]. Retrieved from https://www.youtube.com/watch?v=8NNRpxBTpk8&t=153s
I really enjoyed this article! As an athlete I am super picky about what goes into my body 24-ish hours before a match (Well all the time but particularly during this time). At our games we also have cold water and gatorade. I've always heard about what you should and should not ingest before and during exercise and I have heard mixed reviews about gatorade. Personally I don't drink gatorade before or during my soccer matches because the sugar in it coats my mouth and gives it a sticky texture. I always drink cold water because I had simple preference for it while exercising. But I am glad to know now that my liking towards cold water is helping me thermoregulate my body. Thats something I had never actually thought about. Its interesting that there are 100's of companies out there making millions off of sports drinks when really you could just get cold water and salt. A lot less appetizing but a lot cheeper.
ReplyDeleteThis article makes me wonder what the optimal recovery solution is? If the optimal hydrating solution is cold water and salt, what simple things could athletes ingest that make them recover to the greatest degree?
Andrew, love how you dove deeper into the information we read about in class. It is crazy how these sports drinks, like Gatorade, are able to label themselves as ideal fueling drinks. As a community member, who did not have this knowledge prior to reading your blog post, assumed that the sport drinks' advertisement was truthful and took it at face value. This brings up the question of whether it is ethically okay for big companies, like Gatorade, to be able to advertise like so. They are not doing their buyers any good, but are they doing their consumers harm? People buying these drinks are under impression that by drinking these products they are hydrating their bodies and are helping them to recover. The experiment, that you talked about in our blog post, shows that these drinks are doing the exact opposite as they say, pulling water out of the cells due to their sugar content. I would say that these companies are causing harm to their buyers by not correctly informing them.
ReplyDeleteMy roommate is studying to become a personal trainer currently and after reading this blog post I was curious to see what her book said about hydration. All throughout I kept reading that the best thing to do is to increase the amount of intake of water before, during and after exercise. It never specified on the fact of adding table salt to the water to increase water retention. I understand during exercise you sweat and thus lose sodium, but wouldn’t the intake of sodium via food suffice for that loss? How would you regulate the sodium intake especially because you are only supposed to ingest a certain amount per day? I guess I am asking to elaborate a little further regarding how adding sodium to the water will have beneficial effects on water retention.
ReplyDeleteI also was under the impression that the main purpose of drinking Gatorade was for the electrolytes and not for the carbohydrates. After consuming a meal with carbohydrates, your body stores the excess glycogen, which is then converted to ATP when working out. This means, your body should have enough energy reserved if you have eaten before an exercise session. How does the electrolyte content of the drink affect the body in comparison with the sugar content? Do they balance each other out?
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DeleteHi Abby,
DeleteI just came across this blog post and saw your comment and wanted to provide some insight.
There are two strategies to counteract the loss of plasma volume during prolonged exercise. Your kidneys do their best to excrete excess sodium from your diet and keep it at a stable level. The idea is that you're manipulating plasma volume temporarily to increase muscular performance.
1)If you ingest sodium with water PRIOR to working out, your body will temporarily have a higher plasma volume because the increased salt will draw more water into your blood due to osmolarity. This method will prepare your body for the loss of salt and water.
2) If you ingest sodium with water DURING your workout, you will replenish your plasma volume levels to its normal state.
As for your question about carbohydrates, yes, you are right. People do drink gatorade for the electrolytes. Salt is also an electrolyte and drinking gatorade will rehydrate you while replenishing your electrolyte levels (refer to strategy 2 above). While converting glycogen to ATP is an excellent way of generating energy, there are also other methods of ATP generation that can depend on your hormone levels and the type of exercise you're doing. For example, when women have high levels of estrogen during the second half of their menstrual cycle, their body is reluctant to use glycogen stored in their liver and relies on energy from fat metabolism. Therefore, they may need additional carbs to fuel their workout because that glycogen source is blocked off.
This was a great post, Andrew! During my training for the Boulder Half-Ironman, I constantly tried to figure out which drinks were the best for hydration. Scratch was ultimately what I used during the bike portion along with just plain water!
ReplyDeleteIt is interesting to see that the sports drinks could actually dehydrate you more. Brands like Gatorade and Powerade emphasize their ELECTROLYTES but fail to advertise how the sugar really affects your body. I think if these companies advertised what these electrolytes really were, then people wouldn't be so inclined to buy them. I don't think people really realize what the electrolytes are and that they can obtain them other ways without the added sugar. I found that during my training, my diet was the best way to obtain all of these nutrients. Adding salt to whatever I was eating the night before and morning of big training days worked for me. I also ate my fair share of bananas to get as much potassium. Believe me, I gave my sodium/potassium pumps a workout.
This also brings up the idea that maybe we shouldn't be serving these high sugar sports drinks at sporting events like Akinaf436 mentioned above. Individual institutions that aren't paid by big companies like Gatorade to serve these drinks. I think there should be some physiological consideration as to what we are serving our young athletes.