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Purpose: To critically examine the research on novel supplements and strategies designed to enhance carbohydrate delivery and/or availability., Methods: Narrative review., Results: Available data would suggest that there are varying levels of effectiveness based on the supplement/supplementation strategy in question and mechanism of action. Novel carbohydrate supplements including multiple transportable carbohydrate (MTC), modified carbohydrate (MC), and hydrogels (HGEL) have been generally effective at modifying gastric emptying and/or intestinal absorption. Moreover, these effects often correlate with altered fuel utilization patterns and/or glycogen storage. Nevertheless, performance effects differ widely based on supplement and study design. MTC consistently enhances performance, but the magnitude of the effect is yet to be fully elucidated. MC and HGEL seem unlikely to be beneficial when compared to supplementation strategies that align with current sport nutrition recommendations. Combining carbohydrate with other ergogenic substances may, in some cases, result in additive or synergistic effects on metabolism and/or performance; however, data are often lacking and results vary based on the quantity, timing, and inter-individual responses to different treatments. Altering dietary carbohydrate intake likely influences absorption, oxidation, and and/or storage of acutely ingested carbohydrate, but how this affects the ergogenicity of carbohydrate is still mostly unknown., Conclusions: In conclusion, novel carbohydrate supplements and strategies alter carbohydrate delivery through various mechanisms. However, more research is needed to determine if/when interventions are ergogenic based on different contexts, populations, and applications.

The purpose of this study was to determine the effect of a whole-food protein (cottage cheese, CC) consumed before sleep on next-morning resting energy expenditure (REE), RER and appetite compared with an isoenergetic/isonitrogenous casein protein (CP) supplement and placebo (PL) in active women. In a beverage-blinded, randomised, cross-over design, ten active women (age, 23·1 (sd 1·9) years; body fat, 22·0 (sd 4·6) %) consumed pre-sleep CC (30 g of protein, 10 g of carbohydrate and 0 g of fat) or energy- and protein-matched liquid CP or PL (0 kJ). Participants arrived at 18.00 hours for an overnight stay in the laboratory. At 30-60 min before normal bed time (2 h post standard meal), participants consumed CC, CP or PL before measurement of REE. Upon waking (05.00-08.00 hours), REE was repeated and subjective appetite was recorded. Statistical analyses were conducted using repeated-measures ANOVA (SPSS). Significance was accepted at P≤0·05. There were no significant differences in acute REE (CC, 7217 (sd 1368); CP, 7188 (SD 895); PL, 7075 (sd 1108) kJ/d, P=0·95), acute RER (0·79 (sd 0·05), P=0·56), morning REE (CC, 5840 (sd 1225); CP, 5694 (sd 732); PL, 5991 (sd 903) kJ/d, P=0·79) or morning RER (0·77 (sd 0·03), P=0·52). Subjective measures of appetite were not different between groups. In active women, pre-sleep consumption of CC does not alter REE or RER more than a CP or PL beverage. These data suggest that the metabolic response from whole-food protein do not differ from the metabolic response of liquid protein.

Background: While it is well established that dietary nitrate reduces the metabolic cost of exercise, recent evidence suggests this effect is maintained 24 h following the final nitrate dose when plasma nitrite levels have returned to baseline. In addition, acute dietary nitrate was recently reported to enhance peak power production. Our purpose was to examine whether chronic dietary nitrate supplementation enhanced peak power 24 h following the final dose and if this impacted performance in a heavily power-dependent sport., Methods: In a double-blind, randomized, crossover design, maximal aerobic capacity, body composition, strength, maximal power (30 s Wingate), endurance (2 km rowing time trial), and CrossFit performance (Grace protocol) were assessed before and after six days of supplementation with nitrate (NO) (8 mmol·potassium nitrate·d -1 ) or a non-caloric placebo (PL). A 10-day washout period divided treatment conditions. Paired t -tests were utilized to assess changes over time and to compare changes between treatments., Results: Peak Wingate power increased significantly over time with NO (889.17 ± 179.69 W to 948.08 ± 186.80 W; p  = 0.01) but not PL (898.08 ± 183.24 W to 905.00 ± 157.23 W; p  = 0.75). However, CrossFit performance was unchanged, and there were no changes in any other performance parameters., Conclusion: Consuming dietary nitrate in the potassium nitrate salt form improved peak power during a Wingate test, but did not improve elements of strength or endurance in male CrossFit athletes.

Endurance athletes rarely compete in the fasted state, as this may compromise fuel stores. Thus, the timing and composition of the pre-exercise meal is a significant consideration for optimizing metabolism and subsequent endurance performance. Carbohydrate feedings prior to endurance exercise are common and have generally been shown to enhance performance, despite increasing insulin levels and reducing fat oxidation. These metabolic effects may be attenuated by consuming low glycemic index carbohydrates and/or modified starches before exercise. High fat meals seem to have beneficial metabolic effects (e.g., increasing fat oxidation and possibly sparing muscle glycogen). However, these effects do not necessarily translate into enhanced performance. Relatively little research has examined the effects of a pre-exercise high protein meal on subsequent performance, but there is some evidence to suggest enhanced pre-exercise glycogen synthesis and benefits to metabolism during exercise. Finally, various supplements (i.e., caffeine and beetroot juice) also warrant possible inclusion into pre-race nutrition for endurance athletes. Ultimately, further research is needed to optimize pre-exercise nutritional strategies for endurance performance.

Purpose: To determine the effects of dietary nitrate (NO3−) supplementation on physiological responses, cognitive function, and performance during heavy load carriage in military cadets. Methods: Ten healthy males (81.0 ± 6.5 kg; 180.0 ± 4.5 cm; 56.2 ± 3.7 ml·kg·min−1VO2max) consumed 140 mL·d−1 of beetroot juice (BRJ; 12.8 mmol NO3−) or placebo (PL) for six d preceding an exercise trial, which consisted of 45 min of load carriage (55% body mass) at 4.83 km·h−1 and 1.5% grade, followed by a 1.6-km time-trial (TT) at 4% grade. Gas exchange, heart rate, and perceptual responses were assessed during constant-load exercise and the TT. Cognitive function was assessed immediately prior to, during, and post-exercise via the psychomotor vigilance test (PVT). Results: Post-TT HR (188 ± 7.1 vs. 185 ± 7.4; d = 0.40; p = 0.03), mean tidal volume (2.15 ± 0.27 vs. 2.04 ± 0.23; p = 0.02; d = 0.47), and performance (770.9 ± 78.2 s vs. 809.8 ± 61.4 s; p = 0.03; d = 0.63) were increased during the TT with BRJ versus PL. There were no effects of BRJ on constant-load gas exchange or perceptual responses, and cognitive function was unchanged at all time points. Conclusion: BRJ supplementation improves heavy load carriage performance in military cadets possibly as a result of attenuated respiratory muscle fatigue, rather than enhanced exercise economy. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the effects of a novel maltodextrin-fructose hydrogel supplement (MF-H) on cycling performance and gastrointestinal distress symptoms.Methods: Nine endurance-trained male cyclists (age = 26.1 ± 6.6, mass = 80.9 ± 10.4 kg, VO2max = 55.5 ± 3.6 mL·kg·min-1) completed three experimental trials consisting of a 98-min varied-intensity cycling protocol followed by a performance test of ten consecutive sprint intervals. In a cross-over design, subjects consumed 250 mL of a treatment beverage every 15 min of cycling. Treatments consisted of 78 g·hr-1 of either (a) MF-H, (b) isocaloric maltodextrin-fructose (ratio-matched 2:1; MF), and (c) isocaloric maltodextrin only (MD).Results: There were no differences in average sprint power between treatments (MF-H, 284 ± 51 W; MF, 281 ± 46 W; and MD, 277 ± 48 W), or power output for any individual sprint. Subjective ratings of gastrointestinal distress symptoms (nausea, fullness, and abdominal cramping) increased significantly over time during the cycling trials, but few individuals exceeded moderate levels in any trial with no systematic differences in gastrointestinal discomfort symptoms observed between treatments.Conclusions: In conclusion, ingestion of a maltodextrin/fructose hydrogel beverage during high-intensity cycling does not improve gastrointestinal comfort or performance compared to MF or MD beverages. [ABSTRACT FROM AUTHOR]

Background: The present study investigated the effects of a multi-ingredient dietary supplement (MIDS) containing caffeine, conjugated linoleic acid (CLA), green tea, and branched-chain amino acids (BCAA) taken for 8 weeks on body composition, blood lipid profile, glucose, insulin, adiponectin, leptin, and high-sensitivity C-reactive protein (hs-CRP) in overweight and obese men and women. Methods: Twenty-two participants completed the study (PL, n = 11; 7 women, 4 men; age, 34 ± 3.5 years; height, 169.2 ± 3.3 cm; body mass, 96.9 ± 6.8 kg; BMI, 34.1 ± 1.8 kg/m2; MIDS, n = 11; 9 women, 2 men; age, 36 ± 3.4 years; height, 173.2 ± 2.9 cm; body mass, 91.9 ± 5.6 kg; BMI, 30.0 ± 1.5 kg/m2). Participants were randomly assigned and stratified by body fat percentage to two groups: 1) a soybean oil placebo (PL) or 2) MIDS. Each group consumed two pills with breakfast and two pills with lunch. Body composition and android fat, waist and hip circumferences, blood pressure and heart rate were measured at baseline and after 8 weeks of supplementation. Results: There were no significant changes for any of the variables of body composition. Feelings of hunger were significantly higher in MIDS versus PL with no changes observed in satiety or desire to eat. Heart rate and blood pressure were unaltered in MIDS after 8 weeks of supplementation. Furthermore, lipid profile, food intake, mood state variables, fasting blood glucose, and endocrine markers did not significantly change regardless of group. Conclusion: MIDS intake does not appear to alter body composition or markers of cardiovascular health versus PL. Moreover, MIDS may actually increase feelings of hunger versus PL. [ABSTRACT FROM AUTHOR]