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Finish First Insider, Issue #43
February 02, 2009
Please enjoy another issue packed with evidence-based information about sports performance training and news about current events at Finish First Sports Performance. If you find value in this e-newsletter, please forward this message to your teammates, coaches, or other parents of hard working athletes.
Congratulations to the Pittsburgh Steelers! NFL Champions!
Fluid and Carbohydrate Consumption During Sporting EventsBy Coach J. Hoy, CSCS, USAW, Jump Stretch, Inc. Certified,
Elite Performance Scientist
The sports drink industry is a multi-billion dollar industry, headlined by names such as Gatorade, Powerade, and Vitamin Water. Advertisements would lead us to believe that these beverages are great for drinking any time of the day, regardless of activity, with no specific purpose rather than to help provide energy that we “need.” The truth is that these beverages may be beneficial, depending on the type of exercise we are doing, the intensity at which we are doing it, our level of hydration (or how much sweat we are losing), and the carbohydrate concentration of the drink (you can get this by looking at the % on the label).
The following article will provide recommendations backed by research and suggestions from professional organizations that are not in the business of selling sports beverages or carbohydrate supplements. For the purpose of this article, pre-event meals or carbohydrate consumption were not considered—only the possible advantage of carbohydrate consumption during an event.
The American College of Sports Medicine recommends that athletes attempt to drink 6 to 12 oz. of fluid in 15 to 20 minute intervals, beginning at the start of the event to help prevent dehydration, and to facilitate an increased rate of gastric emptying. They also recommend that athletes consume a carbohydrate (CHO) beverage during an event lasting longer than one hour, with optimal carbohydrate concentrations between 4% and 8%. An increased rate of gastric emptying speeds up the rate at which the carbohydrates will enter the blood and then in turn can be used for ATP production (1).
Carbohydrate beverages with greater than 8% carbohydrate concentration are not recommended for consumption during events, and they are best suited for post exercise glycogen replenishment, These higher content carbohydrate beverages have been shown to decrease the rate of gastric emptying, which would result in a slower rate of potential usage for energy production (1).
Studies have shown that carbohydrate consumption has increased exercise time to fatigue during longer events, during high intensity events in the heat (60%VO2max, and 75%VO2max), and they have also shown improved performance in sports like cycling, long distance running, soccer, hockey and basketball (3)(5)(6).
Research conducted using commercially available sports drinks has shown that there is little evidence that one drink is better than another (4). It is recommended that if an athlete consumes a sports drink, s/he uses one that is palatable, fits in the 4% to 8% CHO concentration range, and does not cause any gastro-intestinal (GI) distress.
While there is much research on specific carbohydrate sports beverages, there are additional types of carbohydrate beverages that have been used. For example, fruit juices (10% - 15% CHO concentration), soft drinks (10% - 11% CHO concentration), cordials, and additional drink concentrates have all been tested. Because these beverages contain above 10% CHO concentration, they are not recommended for consumption for during an event. (9).
Some research has even been conducted comparing the effects of various types of carbohydrate, including fructose, galactose, maltose, sucrose, glucose polymers-matlodextrins, and starch. The research showed that that not all of these CHO sources are equally effective with glucose, sucrose, maltose, maltodextrins and amylopectin (a type of starch) producing higher oxidation rates, and therefore more beneficial in energy production during athletic events lasting more than 1 hour (8).
Another study compared the effect of a CHO beverage containing glucose to the effect of a CHO beverage containing glucose and fructose. The results showed that there was a greater performance enhancement effect produced by consumption of the glucose and fructose beverage, suggesting that it would be more beneficial to consume a beverage with multiple types of carbohydrates (5). Since it has been found that glucose and fructose are absorbed by different intestinal transporters, by combining the two CHO sources does not slow down gastric emptying (5).
Anecdotal evidence has suggested that the glycemic index of a carbohydrate would have an effect on the performance outcome of the individual. A 2004 study compared the effect(s) of the consumption of honey (low glycemic index rating of 35) or dextrose (high glycemic index of 100) during a 64km cycling time trial. The results showed that there was no noticeable difference between the consumption of the high glycemic dextrose and the low glycemic honey (7).
In a personal interview in 2000, Lesli Bonci, RD, recommended CHO supplements such as gummy bears and gummy worms for events lasting over an hour. I have found that these are especially popular with athletes under 12 years of age, and are meant to be used in addition to consumption of water for fluid replacement during exercise. (2).
In addition to the studies showing that carbohydrate supplementation is beneficial during events lasting about 90 minutes, some studies have shown that CHO supplementation may also be beneficial during intermittent exercise of shorter duration (4). Shorter events (bouts of continuous exercise) of submaximal intensity would not need any additional CHO supplementation, but shorter events that are higher intensity or involve intermittent exercise, such as ice hockey, or multi-event athletes (or tournaments) may deplete the muscle glycogen stores earlier in the event which would facilitate a need for CHO supplementation. CHO supplementation would provide readily available glucose in the blood which can then in turn be converted to glycogen for use in ATP production during the intermittent or high intensity exercise. It should also be noted that during sporting events less than 30 minutes of continuous exercise, fluid replacement is a higher priority than replacing CHO in the muscle or liver (9).
1. American College of Sports Medicine. Position Stand: Exercise and fluid replacement. Medicine and Science in Sports and Exercise, 28:i-vii, 1996.
2. Bonci, Lesli. Personal Interview. 18 July 2000.
3. Carter, Jeukendrup, Mundel, & Jones. (2003). Carbohydrate supplementation improves moderate and high-intensity exercise in the heat. Pflügers Archiv: European Journal of Physiology, 446(2), 211-219.
4. Coombes, , & Hamilton, . (2000). The effectiveness of commercially available sports drinks. Sports Medicine, 29(3), 181-209.
5. Currell, & Jeukendrup, A. (2008). Superior endurance performance with ingestion of multiple transportable carbohydrates. Medicine & Science in Sports & Exercise, 40(2), 275-281.
6. Davis, Welsh, & Alderson. (2000). Effects of carbohydrate and chromium ingestion during intermittent high-intensity exercise to fatigue. International Journal of Sport Nutrition & Exercise Metabolism, 10(4), 476-485.
7. Earnest, Lancaster, Rasmussen, Kerksick, Lucia, Greenwood, et al. (2004). Low vs. high glycemic index carbohydrate gel ingestion during simulated 64-km cycling time trial performance. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 18(3), 466-472.
8. Jeukendrup, & Jentjens, R. (2000). Oxidation of carbohydrate feedings during prolonged exercise: Current thoughts, guidelines and directions for future research. Sports Medicine, 29(6), 407-424.
9. Pearce . (1996). Nutritional analysis of fluid replacement beverages. Australian Journal of Nutrition & Dietetics, 53(4), S35.
Vitamin C Needs in AthletesBy Heather R Mangieri, MS, RD, LDN, Finish First Sports Performance Nutrition Advisor
Vitamin C, also known as ascorbic acid, is one of the water soluble vitamins essential to many body processes. Among them include collagen synthesis, the formation of certain hormones & neurotransmitters, regulation of amino acids, folic acid & cholesterol, participation in wound healing and its assistance in the digestion of iron. Further, it is involved in a number of biochemical pathways that are important to exercise metabolism and the health of active individuals. Most notably may be its work as an antioxidant.
The current RDA for vitamin C is 90 mg/day for males ages 19 and older and 75 mg/day for females over age 19. Slightly lower amounts are recommended for teenage males and females aged 14-18, 75 and 65 mg/day, respectively. Even lower amounts are suggested for children. There has been some evidence to suggest that active individuals may need more vitamin C due to the increased stress associated with exercise.
Research regarding vitamin C consumption in athletes is considerable. Perhaps because it is one of the vitamins that athletes consume in rather substantial amounts. Another possibility is that exercise is a known stressor and vitamin C is known for its immune boosting properties. Early and recent research show that vitamin C supplementation improves physical performance in those that are deficient, but a thorough analysis of these studies suggest that vitamin C supplementation does not increase performance capacity in those that are not deficient (1). No solid experimental research supports the use of mega doses of 5-10 grams that some athletes take, even for the prevention of the common cold (2, 3).
On the other hand, some investigators still testify that active individuals need slightly more vitamin C than the RDA. It has been documented in at least one well regarded study that vitamin C protects against oxidative stress in endurance and ultra endurance athletes, especially preventing upper respiratory tract infections (URTI) (4). While performance enhancement could not be proven, perhaps equally important from a health standpoint is immunity. The current guidelines reflect that research and the assumption of others.
Individuals that consistently exercise may require at least 100 mg/day of vitamin C to maintain normal vitamin C status and protect the body from the oxidative stressors of exercise (5). This amount is easily obtainable from the diet. Individuals who are competing in ultra endurance events may require up to 500 mg/day. This elevated amount may require the use of a supplement in order to meet the higher recommendation. Either way it is important to remember that vitamin C does have a tolerable upper limit of 2,000 mg/day which should not be exceeded.
1. Bell, C., et al. 2005. Ascorbic acid does not affect the age-associated reduction in maximal cardiac output and oxygen consumption in healthy adults. Journal of Applied Physiology 98:845-49.
2. Audera C, Pattulny RV, Sander BH, Douglas RM. Mega-dosing vitamin C in treatment of the common cold: a randomized controlled trial. Med J Aust. 2001;175:359-362
3. Douglas RM, Chalker EB, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database System Review. 2000;2:CD000980.
4. Evans W. Vitamin E, vitamin C and exercise. Am J of Clinical Nutrition. 2007:72(suppl):647s-652s.
5. Keith RE. Ascorbic acid. In: Wolinsky I, Driskell JA, eds. Sports Nutrition. Boca Raton, Fla: CRC Press; 1997:29-45.
Meeting the Increased Vitamin C Needs of Athletes: Practical AdviceBy Heather R Mangieri, MS, RD, LDN, Finish First Sports Performance Nutrition Advisor
Now that you understand your increased vitamin C demand, how can you meet needs? One important thing to remember is that vitamin C is vulnerable to heat and is destroyed by oxygen. Food will lose some of the vitamin during processing and/or preparation. The best sources are whole, raw foods. The following is a list of foods that are rich in vitamin C and will help you reach your goal of 100 mg/day.
½ cup Orange Juice= 62 mg 1 cup Red Tomato= 34 mg ½ c raw Sweet red pepper= 142 mg 2 cups Romaine Lettuce= 26 mg ½ cup Strawberries= 43 mg 1 Orange= 70 mg ½ cup Sweet potato= 20 mg 1 Kiwi= 57 mg
Motivational Sports QuotesIf it's the ultimate game, how come they're playing it again next year?
-- Duane Thomas, Cowboys RB Super Bowl VI
I'll be glad to leave here. I feel like eating palm trees. I don't like this place. It's for people with arthritis. They come here to play golf and to die.
(After hearing that Redskins OG Russ Grimm had said that he would run over his own mother to win the Super Bowl)
I'd run over Russ Grimm's mother to win the Super Bowl, too.
You've got to stand up and do your own battles. My daddy taught me that a long time ago, that you fight your own battles. The only way to shut everybody up is to win.
The Store is Now Open For Business!Finish First Sports Performance Logo Apparel and Items
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Take a look at the logo apparel store.
Coming SoonFinish First Sports Performance Discovery Days
Curious about what we do or what we can do for you? Attend one of our Discovery Day presentations and have all of your questions answered AND learn about preparing for sports success.
Summer Speed and Acceleration Camps
Sports Performance Seminars for Coaches, Parents, and Athletes
ATTENTION: Finish First Sports Performance Embroidered HoodiesPLEASE READ THIS CAREFULLY.
The Finish First Sports Performance embroidered logo Hoodies are expected to be delivered the week of February 4th, 2009. If you have ordered a Hoodie, you will need to pay before they are delivered. Please contact Jeremy about payment. (412)-787-5070
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Thanks again for subscribing to this free e-newsletter. I hope you enjoy reading it as much as I enjoy writing it. I look forward to your feedback as I continue to research to bring you the most current scientific training information available.
Should you have any specific article requests or questions, email me at firstname.lastname@example.org. Please visit www.finishfirstsports.com for detailed sports performance training information and programs offered exclusively by Finish First Sports Performance.
Yours In Training,
Coach Jeremy S. Hoy, CSCS, USAW, Jump Stretch, Inc. Certified,
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