Scientific Publications

Through presentations at professional meetings and publications in leading peer-reviewed journals, research supported by the Beverage Institute For Health & Wellness and The Coca-Cola Company is making significant contributions to the science of hydration and nutrition, and increasing understanding of the positive role that beverages and their ingredients can play in supporting human health, performance, and well-being.

Bone Health

Vitamin D in foods: Development of the US Department of Agriculture database. Holden JM, Lemar LE, and Exler J. Am J Clin Nutr 2008; 87(suppl):1092S– 6S.
Abstract

• Context: Specific data on vitamin D2 and vitamin D3 are needed to enable the assessment of vitamin D dietary intake. These forms of the vitamin can occur in foods, both naturally or from fortification. The Nutrient Data Laboratory at the Beltsville Human Nutrition Research Center, Agricultural Research Service, US Department of Agriculture collaborated with vitamin D experts in an analytic project with 2 major goals: 1) to review and develop methods for analyzing a variety of food items for vitamin D content and 2) to sample and analyze foods considered to be major contributors of vitamin D. During 2007, analysts from up to 6 laboratories compared methods, made modifications in some cases, and validated results with quality-control samples of similar food types in preparation for the analysis of sampled foods. The Nutrient Data Laboratory has prioritized foods for analysis and has identified the following as important contributors of vitamin D: finfish and shellfish, naturally occurring sources, and fortified foods such as milk, calcium-fortified orange juice, breakfast cereals, American cheese, margarines, and yogurt. A nationwide multistage sampling plan was designed and conducted to select and procure representative sample units of all such foods. After analysis of these food samples and review of the results, acceptable values for vitamin D2 and D3 will be disseminated in the National Nutrient Database for Standard Reference.

Vitamin D2 is as effective as Vitamin D3 in maintaining circulating concentrations of 25-Hydroxyvitamin D. Holick MF, Biancuzzo RM, Chen TC, Klein EK, Young A, Bibuld D, Reitz R, Salameh W, Ameri A, Tannenbaum AD. J Clin Endocrinol Metab. 2008 Mar;93(3):677-81. Epub 2007 Dec 18. PMID: 18089691.
Abstract

• Context: Two reports suggested that vitamin D2 is less effective than vitamin D3 in maintaining vitamin D status. Objective Determine whether vitamin D2 was less effective than vitamin D3 in maintaining serum 25-hydroxyvitamin D levels or increased the catabolism of 25-hydroxyvitamin D3. Subjects and Design This was a randomized, placebo-controlled, double-blinded study of healthy adults ages 18-84 years who received either placebo, 1,000 IU of vitamin D3, 1,000 IU of vitamin D2, or 500 IU of vitamin D2 plus 500 IU of vitamin D3 daily for 11 weeks at the end of the winter. Results Sixty percent of the healthy adults were vitamin D deficient at the start of the study. The circulating levels of 25-hydroxyvitamin D (mean +/- SD) increased to the same extent in the groups that received 1,000 IU daily as vitamin D2 (baseline 16.9 +/- 10.5 ng/ml; 11 weeks 26.8 +/- 9.6 ng/ml); vitamin D3 (baseline 19.6 +/- 11.1 ng/ml; 11 weeks 28.9 +/- 11.0 ng/ml) or a combination of 500 IU vitamin D2 and 500 IU vitamin D3, (baseline 20.2 +/- 10.4 ng/ml; 11 weeks 28.4 +/- 7.7 ng/ml). The 25-hydroxyvitamin D3 levels did not change in the group that received 1,000 IU vitamin D2 daily. 1,000 IU of vitamin D2 or vitamin D3 did not raise 25-hydroxyvitamin D levels in vitamin D deficient subjects above 30 ng/ml. Conclusion: 1,000 IU of vitamin D2 daily was as effective as 1,000 IU of vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.

A combination of prebiotic short- and long-chain insulin-type fructans enhances calcium absorption and bone mineralization in young adolescents. Abrams SA, Griffin IJ, Hawthorne KM, Liang L, Gunn SK, Darlington G, Ellis KJ Am J Clin Nutr. 82(2):471-476, 2005.
Abstract

• Background: Short-term studies in adolescents have generally shown an enhancement of calcium absorption by inulin-type fructans (prebiotics). Results have been inconsistent; however, and no studies have been conducted to determine whether this effect persists with long-term use.
• Objective: The objective was to assess the effects on calcium absorption and bone mineral accretion after 8 wk and 1 y of supplementation with an inulin-type fructan. DESIGN: Pubertal adolescents were randomly assigned to receive 8 g/d of a mixed short and long degree of polymerization inulin-type fructan product (fructan group) or maltodextrin placebo (control group). Bone mineral content and bone mineral density were measured before randomization and after 1 y. Calcium absorption was measured with the use of stable isotopes at baseline and 8 wk and 1 y after supplementation. Polymorphisms of the Fok1 vitamin D receptor gene were determined.
• Results: Calcium absorption was significantly greater in the fructan group than in the control group at 8 wk (difference: 8.5 +/- 1.6%; P < 0.001) and at 1 y (difference: 5.9 +/- 2.8%; P = 0.04). An interaction with Fok1 genotype was present such that subjects with an ff genotype had the least initial response to fructan. After 1 y, the fructan group had a greater increment in both whole-body bone mineral content (difference: 35 +/- 16 g; P = 0.03) and whole-body bone mineral density (difference: 0.015 +/- 0.004 g/cm(2); P = 0.01) than did the control group.
• Conclusion: Daily consumption of a combination of prebiotic short- and long-chain inulin-type fructans significantly increases calcium absorption and enhances bone mineralization during pubertal growth. Effects of dietary factors on calcium absorption may be modulated by genetic factors, including specific vitamin D receptor gene polymorphisms.
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Vitamin D intakes by children and adults in the United States differ among ethnic groups. Moore C, Murphy M, Holick M. J Nutr. 2005; 135:2478-2485.
Abstract

• Concerns about vitamin D status in the United States have resurfaced due to increasing reports of insufficiency and deficiency. Few foods contain vitamin D naturally, and currently few foods are fortified in the United States. Intakes of vitamin D in the United States from food and food plus supplements by age, sex, and race/ethnicity group were estimated. Individuals 1 y old who participated in the 1999–2000 National Health and Nutrition Examination Survey (NHANES 1999–2000) were included in the analysis. Vitamin D intake by non-Hispanic (NH) white, NH black, Mexican American, and all individuals in the United States was estimated and compared with recommended levels. Vitamin D intakes were highest among children and teenagers, and lowest in the oldest age categories. Among children age 1–8 y, adequate intake (AI) levels for vitamin D from food were met or exceeded by 69% of Mexican American, 59% of NH white, and 48% of NH black subpopulations. Among adults 51 y old, only 4% met or exceeded the AI from food alone. Few women 19–50 y old or men and women 51 y old were estimated to consume recommended vitamin D levels from food. Mean dietary intakes of vitamin D from food plus supplements were consistently highest among NH white populations, although only small proportions of all those 51 y old had intakes above the recommended levels. The large discrepancy between vitamin D intake by older individuals from food plus supplements and recommended levels, especially for NH black and Mexican American adults, warrants intervention.
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Vitamin D receptor Fok1 polymorphisms affect calcium absorption, kinetics, and bone mineralization rates during puberty. Abrams SA, Griffin IJ, Hawthorne KM, Chen Z, Gunn SK, Wilde M, Darlington G, Shypailo RJ, Ellis KJ. J Bone Miner Res. 2005 Jun;20(6):945-53. Epub 2005 Jan 31.
Abstract

• Few studies of the VDR polymorphisms have looked at calcium metabolism or long-term effects. We measured bone mineralization and calcium metabolic parameters longitudinally in a group of 99 adolescents. We found a significant relationship between calcium absorption and skeletal calcium accretion and the Fok1, but not other VDR or related, genetic polymorphisms. It seems that the Fok1 polymorphism directly affects bone mineralization during pubertal growth through an effect on calcium absorption.
• Introduction: There are few data regarding the relationship between genetic markers for low bone mass and changes in calcium metabolism in childhood or adolescence. We sought to identify the effects of polymorphisms of the vitamin D receptor (VDR) on calcium and bone mineral metabolism in a longitudinal study of pubertal adolescents.
• Materials And Methods: Adolescents (n = 99) received comprehensive stable isotope studies of calcium absorption, bone calcium kinetics, and bone mineralization. Studies were repeated 12 months later. Polymorphisms of putative genetic markers were determined and related to bone mineralization and calcium metabolic finding. Results were analyzed by ANOVA in which changes over time were determined using the initial value as a covariate.
• Results: Polymorphisms of the Fok1 gene of the VDR were significantly related to calcium absorption (p = 0.008) and whole body BMC (p = 0.03) and BMD (p = 0.006). The Fok1 effect on whole body BMD was significant for those with Ca intake >800 mg/day (p < 0.001), whereas for those with Ca intake < or = 800 mg/day, the Fok1 genotype did not have a significant effect on whole body BMD (p = 0.40). The Fok1 genotype was significantly related to the changes during the year in whole body calcium accretion, with the ff genotype having a 63 +/- 20 mg/day deficit compared with the FF genotype (p = 0.008).
• Conclusions: The Fok1 polymorphism of the VDR receptor seems to directly affect bone mineral accretion during pubertal growth through an effect on calcium absorption. The relationship between different genetic polymorphisms and bone mineral metabolism may vary by life stage as well as diet.
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Vitamin D intake in the United States. Moore C, Murphy M, Keast D, Holick M. JADA. 2004; 104:980-983.
Abstract

• Mean intake of vitamin D in the United States was estimated from food and food plus supplements and compared with recommended intake levels. US men, nonpregnant and nonlactating women, and nonbreastfeeding children aged 1 year and older who participated in the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994) or the Continuing Survey of Food Intakes by Individuals 1994-1996, 1998 (CSFII 1994-1996, 1998) were included in the estimates. Intake of vitamin D from food sources and dietary supplements was not meeting recommended levels. The lowest intakes of vitamin D from food were reported by female teenagers and female adults. The highest intakes of vitamin D from food sources were reported by male teenagers. Dairy products were the primary sources of both vitamin D and calcium. Additional food fortification as well as dietary and supplement guidance are needed for the general population.
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Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health. Tangpricha V, Koutkia P, Rieke S, Chen T, and Perez A, Holick M. Am J Clin Nutr. 2003; 77:1478-83.
Abstract

• Background: Fortification of milk with vitamin D may not be adequate for satisfying the vitamin D requirement because of variability in vitamin D content after fortification and because many persons have milk allergy or lactose intolerance. Additional foods need to be fortified with vitamin D.
• Objective: We determined whether vitamin D, a fat-soluble vitamin, is bioavailable in orange juice and skim milk, 2 nonfat beverages.
• Design: On 3 separate occasions, 18 adults ingested 25 000 IU vitamin D2 in 240 mL whole milk or skim milk or in 0.1 mL corn oil applied to toast. A separate, double-blind, randomized, controlled trial investigated whether the consumption of orange juice fortified with vitamin D3 would increase serum 25-hydroxyvitamin D [25(OH)D] concentrations: 14 subjects ingested 240 mL orange juice fortified with 1000 IU vitamin D, and 12 subjects ingested a control orange juice daily for 12 wk.
• Results: Peak serum vitamin D2 concentrations did not differ significantly after the ingestion of vitamin D2 in whole milk, skim milk, or corn oil on toast. After subjects consumed orange juice fortified with 1000 IU vitamin D3 daily for 12 wk, serum 25(OH)D3 concentrations increased by 150%, and serum parathyroid hormone concentrations decreased by 25% compared with baseline; control subjects had a seasonal increase of 45% in 25(OH)D and no significant change in serum parathyroid hormone.
• Conclusions: The fat content of milk does not affect vitamin D bioavailability. Vitamin D fortification at 1000 IU/240 mL orange juice for 12 wk safely increased 25(OH)D3 concentrations in adults.
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Heart Health

Reduced-calorie orange juice beverage with plant sterols lowers C-reactive protein concentrations and improves the lipid profile in human volunteers. Devaraj S., Autret B., Jialal I. Am J Clin Nutr 2006; 84:756–61.Devaraj S., Autret B., Jialal I.
Abstract

• Background: Dietary plant sterols effectively reduce LDL cholesterol when incorporated into fat matrices. We showed previously that supplementation with orange juice containing plant sterols (2 g/d) significantly reduced LDL cholesterol. Inflammation is pivotal in atherosclerosis. High-sensitivity C-reactive protein (hs-CRP), the prototypic marker of inflammation, is a cardiovascular disease risk marker; however, there is a paucity of data on the effect of plant sterols on CRP concentrations.
• Objective: The aim of this study was to examine whether plant sterols affect CRP concentrations and the lipoprotein profile when incorporated into a reduced-calorie (50 calories/240 mL) orange juice beverage.
• Design: Seventy-two healthy subjects were randomly assigned to receive a reduced-calorie orange juice beverage either without (Placebo Bev) or with (1 g/240 mL; Sterol Bev) plant sterols twice a day with meals for 8 wk. Fasting blood was obtained at baseline and after 8 wk of Placebo Bev or Sterol Bev supplementation.
• Results: Sterol Bev supplementation significantly reduced total cholesterol (5%; P < 0.01) and LDL cholesterol (9.4%; P < 0.001) compared with both baseline and Placebo Bev (P < 0.05). HDL cholesterol increased significantly with Sterol Bev (P < 0.02). No significant changes in triacylglycerol, glucose, or liver function tests were observed with Sterol Bev. Sterol Bev supplementation resulted in no significant change in vitamin E and carotenoid concentrations. Sterol Bev supplementation resulted in a significant reduction of CRP concentrations compared with baseline and Placebo Bev (median reduction: 12%; P < 0.005).
• Conclusion: Supplementation with a reduced-calorie orange juice beverage containing plant sterols is effective in reducing CRP and LDL cholesterol and could be incorporated into the dietary portion of therapeutic lifestyle changes.
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Plant sterol-fortified orange juice effectively lowers cholesterol levels in mildly hypercholestrolemic healthy individuals. Devaraj S,Jialal I, Vega-López S. Arterioscler Thromb Vasc Biol. 2004; 24:e25-e28.
Abstract

• Objective: Hypercholesterolemia is a major risk factor for coronary artery disease. Therapeutic lifestyle changes include dietary modifications such as inclusion of phytosterols, which effectively lowers low-density lipoprotein (LDL) cholesterol in margarines and other fats. Their effectiveness in nonfat moieties is not yet established. The aim of this study was to examine if phytosterols alter the plasma lipoprotein profile when incorporated into nonfat orange juice.
• Methods and Results: After a 2-week run-in phase with orange juice, 72 mildly hypercholesterolemic healthy subjects were randomized to receive either placebo orange juice (placebo OJ) or plant sterol-fortified orange juice (sterol OJ) (2g/d) for 8 weeks. Fasting blood was obtained at baseline, after 2 weeks of OJ, and after 8 weeks of placebo/sterol-OJ supplementation. Sterol OJ supplementation significantly decreased total (7.2%), LDL (12.4%), and non-high-density lipoprotein (HDL) cholesterol (7.8%) compared with baseline and compared with placebo OJ (P <0.01). Apolipoprotein B levels were significantly decreased (9.5%) with sterol OJ. There were no significant changes in HDL cholesterol or triglycerides with the sterol OJ. While folate and B12 levels significantly increased, homocysteine levels were unchanged.
• Conclusions: Orange juice fortified with plant sterols are effective in reducing LDL cholesterol and could easily be incorporated into the therapeutic lifestyle changes dietary regimen.
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Hydration

Hydration: Issues for the 21st Century. Grandjean A, Reimers K, and Buyckx M. Nutr Rev. 2003; 61(8): 261–271.
Abstract

• Historically, hydration research reflected critical issues of the day. War, illness, surviving a shipwreck or time in the dessert, supplying fall-out shelters, and space exploration drove hydration research in the first half of the 20th century. The fitness revolution of the 1970s spurred research on dehydration in physically active people and athletes. The 1990s introduced the “fluid/disease relationship.” What will be the driving force behind hydration research in the 21st century? Where are the gaps in our knowledge? This review provides an overview of issues pertinent to determining future directions in hydration research.
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The effect on hydration of two diets, one with and one without plain water. Grandjean A, Reimers K, Bannick K, Haven M. and Curtis G. J Am Coll Nutr. 2003; 22(2):165-173.
Abstract

• Objective: To measure the effect on hydration of two regimens, one that included drinking water as part of the dietary beverages and one that did not.
• Methods: In healthy, sedentary subjects, two different diets were evaluated for their effect on hydration. Trial A provided plain water to drink as part of the beverages served. Trial B omitted plain water from the beverages served. Twenty-seven males, during two three-day confinement periods, consumed one of two diets in a random, crossover and counterbalanced fashion, while diet, physical activity and environment were controlled and monitored. Body weight and 24-hour urine volumes were measured. Pre- and post-trial urine samples and 24-hour urines were assayed for osmolality, specific gravity, chloride, sodium and potassium, and sodium/potassium ratio was calculated. Twenty-four hour creatinine levels were determined.
• Results: No differences (p > 0.05) were found between trials for body weight or other indicators of hydration status measured.
• Conclusions: Inclusion of plain drinking water compared to exclusion of plain drinking water in the diet did not affect the markers of hydration used in this study.
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The Effect of Caffeinated, Non-Caffeinated, Caloric and Non-Caloric Beverages on Hydration. Grandjean A, Reimers K, Bannick K, and Haven M. J Am Coll Nutr. 2000; 19 (5) 591–600.
Abstract

• Objective: To examine the effect of various combinations of beverages on hydration status in healthy free-living adult males.
• Methods: In a counterbalanced, crossover manner, 18 healthy adult males ages 24 to 39, on four separate occasions, consumed water or water plus varying combinations of beverages. Clinical guidelines were used to determine the fluid allowance for each subject. The beverages were carbonated, caffeinated caloric and non-caloric colas and coffee. Ten of the 18 subjects consumed water and carbonated, non-caffeinated, citrus soft drink during a fifth trial. Body weight, urine and blood assays were measured before and after each treatment.
• Results: Slight body weight loss was observed on all treatments, with an average of 0.30% for all treatments. No differences (p.0.05) among treatments were found for body weight changes or any of the biochemical assays. Biochemical assays conducted on first voids and 24-hour urines included electrolytes, creatine, osmolality and specific gravity. Blood samples were analyzed for hemoglobin, hematocrit, electrolytes, osmolality, urea nitrogen, creatinine and protein.
• Conclusions: This preliminary study found no significant differences in the effect of various combinations of beverages on hydration status of healthy adult males. Advising people to disregard caffeinated beverages as part of the daily fluid intake is not substantiated by the results of this study. The across-treatment weight loss observed, when combined with data on fluid-disease relationships, suggests that optimal fluid intake may be higher than common recommendations. Further research is needed to confirm these results and to explore optimal fluid intake for healthy individuals.
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Micronutrient Nutrition

Bioavailability of iron and zinc from a multiple micronutrient-fortified beverage. Avalos Mishaan A, Zavaleta N, Griffin I, Hilmers D, Hawthorne K, Abrams S J Pediatr. 2004; 145:26-31.
Abstract

• Objective: To test the hypothesis that micronutrient beverages can provide the daily iron and zinc needs of small children.
• Study design: Forty children aged 6 to 9 years were recruited (Lima, Peru). For 4 weeks, they received a daily serving of a beverage containing multiple micronutrients. Over 2 consecutive days, subjects received stable isotope-labeled servings of the beverage with and without a meal as well as an intravenous dose of zinc. Iron and zinc bioavailability were assessed using mass spectrometry.
• Results: Iron absorption was significantly lower with a meal than without (9.8 ± 6.7% versus 11.6 ± 6.9%, P = .04), but zinc absorption was not (24.5 ± 10.7% versus 22.8 ± 7.6%, P = .2). In either case, however, a single daily serving provided most of the iron and zinc requirements for the children.
• Conclusions: Single daily servings of multinutrient-fortified beverages can meet much of the mineral needs for small children. Food has a small inhibitory effect on iron, but not zinc, absorption; therefore, these beverages can be efficacious even when given with a meal.
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A multinutrient-fortified beverage enhances the nutritional status of children in Botswana. Abrams S, Mushi A, Hilmers D, Griffin I, Davila P, Allen L. J Nutr. 2003; 133:1834-1840.
Abstract

• Due to their widespread acceptability, multinutrient-fortified foods and beverages may be useful in reducing micronutrient deficiencies, especially in developing countries. We studied the efficacy of a new fortified beverage in improving the nutritional status of children in Botswana. We screened 311 lower income urban school children, ages 6–11 y, in two primary schools near Gaborone. Children were given seven 240-mL servings weekly of either an experimental beverage (EXP) fortified with 12 micronutrients or an isoenergetic placebo drink (CON) for 8 wk. Weight, mid-upper arm circumference, hemoglobin, retinol, ferritin, vitamin B-12, folate and riboflavin status were measured at baseline and at the end of the study. Plasma zinc and serum transferrin receptors also were measured at study end. A total of 145 children in the EXP group and 118 in the CON group completed the trial. Using multivariate analysis, the changes in mid-upper arm circumference, weight for age and total weight were significantly better in the EXP group than in the CON group (P < 0.01). Ferritin, riboflavin and folate status were significantly better in the EXP group than in the CON group at study end (P < 0.01), but serum vitamin B-12 was not. Zinc was significantly higher and transferrin receptors were significantly lower at the conclusion of the study in the EXP group than in the CON group (P < 0.001). Mean plasma retinol concentrations, which were low (<0.7 µmol/L) in both groups, did not change. We conclude that a micronutrient-fortified beverage may be beneficial as part of a comprehensive nutritional supplementation program in populations at risk for micronutrient deficiencies.
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Sports: Performance & Recovery

Caffeinated Sports Drink: Ergogenic Effects and Possible Mechanisms. Cureton KJ, Warren GL, Millard-Stafford ML, Wingo JE, Trilk J, and Buyckx M. Int J Sport Nutr Exerc Metab. 2007; 17:35-55.
Abstract

• This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. Sixteen highly trained cyclists completed 3 trials: placebo, carbohydrate-electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the first 120 min, followed by a 15-min performance ride. Maximal voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15–23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5% vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.
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Should carbohydrate concentration of sports drink be less than 8% during exercise in the heat? Millard-Stafford M, Spartling, Rosskopf, Snow T. Int J Sport Nutr Exerc Metab. 2005;15(2):117-30.
Abstract

• Our purpose was to determine if sports drinks with 6 and 8% CHO differentially affect physiological responses or run performance in the heat. Ten men ran 32 km while ingesting: placebo (P), 6% carbohydrate-electrolyte (CE6), and 8% carbohydrate-electrolyte (CE8). At 15 km, a 250 mL drink labeled with deuterium oxide (D20) was ingested. Blood glucose and respiratory exchange ratio were significantly higher (P < 0.05) for CE6 and CE8 compared to P. Rectal temperature (at 32 km was higher for CE8 (40.1 ± 0.2 ° C) compared to P (39.5 ± 0.2 ° C) but similar to CE6 (39.8 ± 0.2 ° C). D20 accumulation was not different among drink trials. Run performance was 8% faster for CE8 (1062 ± 31 s) compared to P (1154 ± 56 s) and similar to CE6 (1078 ± 33 s). Confirming the ACSM Position Stand, 8% CE are acceptable during exercise in the heat and attenuate the decline in performance.
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Recovery from run training: Efficacy of a carbohydrate–protein beverage? Millard-Stafford M., Thomas L., Warren G.W, Doyle J.A., Snow T., and Hitchcock K. Int J Sport Nutr Exerc Metab. 2005; 15:610-624.
Abstract

• Post-exercise nutrition is critical to facilitate recovery from training. To determine if added protein (P) or increased carbohydrate (CHO) differentially improves recovery, eight runners ingested: 6% CHO (CHO6), 8% CHO + 2% protein (CHO-P), and isocaloric 10% CHO (CHO10) following a 21-km run plus treadmill run to fatigue (RTF) at 90% VO2max. RTF was repeated after 2 h recovery. After 24 h, a 5 km time trial was performed. Insulin and blood glucose were higher (P < 0.05) following CHO10 compared to CHO-P and CHO6, but did not affect improvement from the first to second RTF (29.6% +/- 6, 40.5% +/- 8.8, 40.5% +/- 14.5) or 5 km time (1100 +/- 36.3, 1110 +/- 37.3, 1118 +/- 36.5 s). CK was not different, but perceived soreness with CHO-P (2.1 +/- 0.5) was lower than CHO10 (5.2 +/- 0.7). Additional calories from CHO or P above that provided in sports drinks does not improve subsequent performance after recovery; but less soreness suggests benefits with CHO-P.
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