Fueling with Gels

Bunch of nutrition on a table
May 31, 2013

Mike Ricci


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There are many forms of carbohydrate including liquids, semi-solids, and solids that offer some performance benefit in triathletes, and some forms are more appropriate to certain types of training sessions and race distances than others. For any racing distance, sports drinks are going to benefit a triathlete the most because not only do they empty from your stomach the quickest, but they also provide all the essentials for improved performance including carbohydrate, electrolytes, and fluids.Consuming carbohydrate during training or competition is what most athletes do to help fuel their performance, but not everyone is the same and may choose a different energy source. Almost all endurance athletes will utilize sports drinks, but there are many options now available allowing for consumption of something different. Energy gels have become very popular in endurance sports. Gels are highly concentrated doses of carbohydrates made into a gelatinous type of consistency. Many triathletes utilize gels because they typically do not have a “heavy” or “gut rot” type of feeling. They are a change in texture and flavor for the athlete who is burnt out on sports drinks and craving something different. Another reason is because gel sources are reasonably painless to take with you since most gels will conveniently fit into shorts or jersey pockets.Since energy gels are essentially concentrated carbohydrates, they provide no fluid by themselves. This is important to know because without fluid the gel will break down extremely slow and not allow you to absorb its contents fully. Therefore, roughly every 1.2 – 1.4 oz of gel, an athlete should follow gel consumption with 10 fl.oz. (295ml) to 16.9 fl.oz. (500ml) water (typical bottled water size). The amount of water you consume with the gel will determine on how fast it will be broken down in the stomach and absorbed in the small intestine. If you consume the full 500ml, the gel will digest similar to a sports drink. The less water you take in the slower your absorption becomes. Basically this means if the rate of fluid and carbohydrate exceeds the absorption capacity of the intestine good chance you will develop diarrhea. If you are not utilizing the gel as a fuel source properly you may end up with a tale of nutritional disaster that includes cramps, gastrointestinal (GI) tract issues, along with a decline in your performance.

The role and understanding of the GI tract is vital to a triathlete in regards to proper nutrition and regulating the absorption of a drink or gel with fluid to allow optimal delivery of the nutrients into circulation of the body. Before the human body can actually utilize the contents of the energy gel consumed it first must be emptied from the stomach and absorbed by the small intestine so the carbohydrates can be transported to the appropriate areas in the body.

So let’s break this down from the beginning of consumption and go step by step. After consuming your favorite energy gel it will travel through the esophagus and enter the stomach, which functions as a reservoir that regulates the rate at which the ingested gel will enter the small intestine. Almost entirely all water and nutrients are absorbed in your small intestine. Knowing this, the rate of absorption is effected by how fast the contents of the gel and fluid are emptied from your stomach. Basically, any delay to the gastric emptying rate will have a negative effect when your body is in high demand for energy. This is why consuming fluids with your gel is essential. Another reason why is the volume of any liquids, gels, and solids along with what they are made of are important factors in choosing your nutrition plan in hopes to allow for regulating your gastric emptying rate. Carbohydrate has been shown to increase fluid uptake in the small intestine. What this tells us is that the components of the gel and water are strongly associated and equally important when it comes to absorption of each other.

Following ingestion of a single gel with fluid or sports drink, there is an initial fast phase of gastric emptying when the volume in the stomach (gastric) is at its maximum and as that volume decreases so does the emptying rate. But the rate of emptying in the stomach can be maintained or optimized. By refilling the stomach with sports drink or gels and fluid at timed intervals (i.e. every 20-30 minutes), the volume in the stomach can be kept high and the emptying rate can be maintained. Practice your limits with caution, if you overfill the stomach you cause yourself a great deal of GI distress while slowing your gastric emptying rate.

How is your absorption affected at high intensity exercise? Research has shown at high levels of intensity, roughly at 75% of your maximum effort, is where you will begin to see a decrease in gastric emptying. Your emptying rate will greatly decrease as intensity increases. In order to know how exercise will effect your gastric emptying it matters how long you exercise for, and at what intensity you are performing at. Usually at such high intensities known to inhibit gastric emptying, the duration of those exercises will be too short for fluid and energy to be providing much benefit in performance aid.

To simplify this, the greater your gastric emptying rate, the higher your absorption rate will be in the small intestine. The presence of carbohydrate with fluid will promote water absorption in addition to supplying an energy source to the working muscles. Be careful, by increasing the carbohydrate contents in your stomach too much will slow gastric emptying and remember that the emptying rate of liquids are faster than that of solids. Regularly ingest carbohydrate on timed intervals throughout exercise lasting more than an hour. The quickest humans can utilize that carbohydrate is approximately 0.8-1.0 gram per hour (approximately 1 gram carbohydrate for every minute of exercise ~60g per hour) no matter how much carbohydrate you take in. Research has shown us if you take in at least .7 grams carbohydrate per kilogram body weight every hour of exercise you will be able to sustain your exercise. There are some athletes that cannot utilize carbohydrates as fast as others and then some are able to significantly take on greater amounts as been reported as high as 1.7g/min. Also, research has shown us that a 6% carbohydrate solution or less is absorbed the fastest as opposed to a solution greater in carbohydrates, something you should know when picking out what to ingest for your workouts and races.

Keep in mind that every athlete is different. You will need to experiment with your choice of gel to find your body’s optimal regimen for carbohydrate intake. Pack gels with you on several training sessions and try taking them at different time intervals with liquid to determine what system works best for you. Remember taking in too much carbohydrate can actually hinder your performance, be sure to find the correct balance that helps you, use the guidelines as a baseline to follow and tweak as needed.
Helpful guidelines and tips• When exercise is less than 45 min: no carbs are typically needed but be sure to maintain your hydration and to fuel yourself with some carbohydrates post-exercise.

• 1-2 hours: up to 30-60g/hr, of carbohydrates (~240 calories). If you are fueling with gels or solids be sure to follow consumption with appropriate amount of water.
• 2 or more hours: up to 60-90g/hr, carbohydrates (~330-360 calories). Maintaining proper nutritional balance is vital when exercising at this duration. Knowing not to overfill your stomach to find that right balance will really help you improve your performance not only in training but in races as well.

Nick Suffredin previously was a Scientist at the Gatorade Sports Science Institute where he worked on testing elite professional athletes to enhance their hydration practices and nutrition intake to improve their performance. He has been part of human performance advisory boards as well as currently provides endurance and nutrition coaching. For coaching and nutrition inquiries Nick can be contacted at: TriSuff1@gmail.com
Costill, D.L. and Saltin, B., Factors limiting gastric emptying during rest and exercise. J. Appl. Physiol. 37: 679, 1974.
Coyle, E.F. and Montain, S.J., Carbohydrate and fluid ingestion during exercise: are there trade offs? Med.sci. sports exerc., 24, 671, 1992.
Gisolfi, C.V., Spranger, K.J, Summers, R.W., Schedl, H.P., and Bleiler, T.L., The effects of exercise on intestinal absorption in humans. J. Appl. Physiol. 7: 2518, 1991.
Hawley, J.A., and Burke, L.M., Effect of meal frequency and timing on physical performance. Brit. J. of Nutr. , 77: S91-103, 1997.
Jentjens, R.L., Jeukendrup, A.E., High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. Br. J. Nutr., Apr; 92(4): 485-92, 2005.
Jeukendrup, A.E., Carbohydrate and exercise performance: the role of multiple transportable carbohydrates. Curr. Opin. Clin. Nutr. Metab. Care. Jul; 13 (4): 452-7.
Jeukendrup, A.E., Moseley, L., Mainwaring, G.I., Samuels, S., Perry, S., Mann, C.H., Exogenous carbohydrate oxidation during ultraendurance exercise. J. Appl. Physiol. Apr; 100(4): 1134-41, 2006.Lambert, G.P., Chang, R.T., Joensen, D., Shi, X, Summers, R.W., Schedl, H.P., and Gisolfi, C.V., Simultaneous determination of gastric emptying and intestinal absorption during cycle exercise. Int. J. Sports Med. 17: 48. 1996.
Maughan, R.J., Leiper, J.B., and McGaw, B.A., Effects of exercise intensity on absorption of ingested fluids, Exper. Physiol., 75, 419, 1990.
Murray, R., The effects of consuming carbohydrate-electrolyte beverages on gastric emptying and fluid absorption during and following exercise. Sports Med. 4; 322, 1987.
Noakes, T.D., Rehrer, N.J., and Maughan, R.J., The importance of volume in regulating gastric emptying. Med. and Sci. in Sports and Exerc. 23: 307, 1991.
Shi, X., and Gisolfi, C.V., Fluid and carbohydrate replacement during intermittent exercise. Sports Med. 3: 157, 1998.
Shi, X., Summers, R.W., Schedl, H.P., Flanagan, S.W., Chang, R., and Gisolfi, C.V., Effects of carbohydrate type and concentration and solution osmolality on water absorption. Med. Sci. Sports and Exerc. 27: 1607, 1995.
Sole, C.C. and Noakes, T.D., Faster gastric emptying for glucose-polymer and fructose solutions than for glucose. Europe. J. Appl. Physiol. 58: 605, 1989.
Smith, J.W., Suffredin, N.M., Peronnet, F., Massicotte, D., Lavoi, C., Zachwieja, J.J., Influence of Ingested Glucose Dose on Oxidation, Endogenous Carbohydrate Utilization and Cycling Time-Trial Performance: 599: Amer. Coll. Sports Med. National Conference, May 30, 2007.
Smith, J.W., Zachwieja, J.J., Peronnet, F., Passe, D.H., Massicotte, D., Lavoi, C., and Pascoe, D.D., Fuel selection and cycling endurance performance with ingestion of [13C]: evidence for a carbohydrate dose response. J. Appl. Physiol. Jun; 108(6): 1520-9. 2010.

Coach Mike Ricci is the Founder and Head Coach for D3 Multisport.  His coaching style is ‘process-focused’ vs. ‘results-focused.’ When working with an athlete, their understanding of how and why they are improving is always going to take precedence over any race result. Yes, there is an end goal, but in over 2 decades of coaching, experience has shown him that if you do the right work, and for the right reasons, the results will follow.

Coach Mike is a USAT Level III Elite Certified Coach, Ironman University Certified Coach, and Training Peaks Level II Certified Coach. He was honored as the USAT Coach of the Year.

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