The performance effect of early versus late carbohydrate feedings during prolonged exercise

Heesch, Matthew; Mieras, Molly E.; Slivka, Dustin

doi:10.1139/apnm-2013-0034

Cited by 5 publications

(2 citation statements)

References 32 publications

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“…When carbohydrate was ingested more frequently, performance was improved. Two contrasting papers that operate as extensions of this work include work by Schweitzer et al [ 51 ] who concluded that preferentially delivering carbohydrate during the first or second half of a controlled cycling exercise bout offered no enhancement of performance, while a similar study design by Heesch and colleagues [ 52 ] indicated that providing carbohydrate consistently throughout or in the latter half of a 2-h cycling exercise bout at 62% of peak power decreased the time it took to cover a prescribed distance (10-km) while cycling. It is important to realize that key differences such as the duration of the exercise bout, the nature of the performance assessment (fixed distance vs. time-to-exhaustion) and amount of carbohydrate that was delivered all differed between these studies and can help to explain the differences in outcomes being reported.…”

Section: Introductionmentioning

confidence: 99%

International society of sports nutrition position stand: nutrient timing

Kerksick

Arent

Schöenfeld

et al. 2017

Journal of the International Society of Sports Nutrition

395

293

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Position statementThe International Society of Sports Nutrition (ISSN) provides an objective and critical review regarding the timing of macronutrients in reference to healthy, exercising adults and in particular highly trained individuals on exercise performance and body composition. The following points summarize the position of the ISSN:Nutrient timing incorporates the use of methodical planning and eating of whole foods, fortified foods and dietary supplements. The timing of energy intake and the ratio of certain ingested macronutrients may enhance recovery and tissue repair, augment muscle protein synthesis (MPS), and improve mood states following high-volume or intense exercise.Endogenous glycogen stores are maximized by following a high-carbohydrate diet (8–12 g of carbohydrate/kg/day [g/kg/day]); moreover, these stores are depleted most by high volume exercise.If rapid restoration of glycogen is required (< 4 h of recovery time) then the following strategies should be considered:aggressive carbohydrate refeeding (1.2 g/kg/h) with a preference towards carbohydrate sources that have a high (> 70) glycemic indexthe addition of caffeine (3–8 mg/kg)combining carbohydrates (0.8 g/kg/h) with protein (0.2–0.4 g/kg/h) Extended (> 60 min) bouts of high intensity (> 70% VO2max) exercise challenge fuel supply and fluid regulation, thus carbohydrate should be consumed at a rate of ~30–60 g of carbohydrate/h in a 6–8% carbohydrate-electrolyte solution (6–12 fluid ounces) every 10–15 min throughout the entire exercise bout, particularly in those exercise bouts that span beyond 70 min. When carbohydrate delivery is inadequate, adding protein may help increase performance, ameliorate muscle damage, promote euglycemia and facilitate glycogen re-synthesis.Carbohydrate ingestion throughout resistance exercise (e.g., 3–6 sets of 8–12 repetition maximum [RM] using multiple exercises targeting all major muscle groups) has been shown to promote euglycemia and higher glycogen stores. Consuming carbohydrate solely or in combination with protein during resistance exercise increases muscle glycogen stores, ameliorates muscle damage, and facilitates greater acute and chronic training adaptations.Meeting the total daily intake of protein, preferably with evenly spaced protein feedings (approximately every 3 h during the day), should be viewed as a primary area of emphasis for exercising individuals.Ingestion of essential amino acids (EAA; approximately 10 g)either in free form or as part of a protein bolus of approximately 20–40 g has been shown to maximally stimulate muscle protein synthesis (MPS).Pre- and/or post-exercise nutritional interventions (carbohydrate + protein or protein alone) may operate as an effective strategy to support increases in strength and improvements in body composition. However, the size and timing of a pre-exercise meal may impact the extent to which post-exercise protein feeding is required.Post-exercise ingestion (immediately to 2-h post) of high-quality protein sources stimulates robust increases in MPS....

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Section: Introductionmentioning

confidence: 99%

International society of sports nutrition position stand: nutrient timing

Kerksick

Arent

Schöenfeld

et al. 2017

Journal of the International Society of Sports Nutrition

395

293

View full text Add to dashboard Cite

show abstract

“…Figure 8.Forest plot shows the effects (red square symbol) of experimental carbohydrate supplementation as compared to a control on exercise outcome for 112 interventions[49][50][51][52][53]78,[80][81][82][83][84][85][86][87][88][89][90][91][92][94][95][96][97][98][99][100][101][102][103][104][105][106][107]109,110,[112][113][114][115][117][118][119]122,124,[129][130][131][132][133][134]…”

mentioning

confidence: 99%

Meta-Analysis of Carbohydrate Solution Intake during Prolonged Exercise in Adults: From the Last 45+ Years’ Perspective

et al. 2021

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Carbohydrate (CHO) supplementation during prolonged exercise postpones fatigue. However, the optimum administration timing, dosage, type of CHO intake, and possible interaction of the ergogenic effect with athletes’ cardiorespiratory fitness (CRF) are not clear. Ninety-six studies (from relevant databases based on predefined eligibility criteria) were selected for meta-analysis to investigate the acute effect of ≤20% CHO solutions on prolonged exercise performance. The between-subject standardized mean difference [SMD = ([mean post-value treatment group–mean post-value control group]/pooled variance)] was assessed. Overall, SMD [95% CI] of 0.43 [0.35, 0.51] was significant (p < 0.001). Subgroup analysis showed that SMD was reduced as the subjects’ CRF level increased, with a 6–8% CHO solution composed of GL:FRU improving performance (exercise: 1–4 h); administration during the event led to a superior performance compared to administration before the exercise, with a 6–8% single-source CHO solution increasing performance in intermittent and ‘stop and start’ sports and an ~6% CHO solution appearing beneficial for 45–60 min exercises, but there were no significant differences between subjects’ gender and age groups, varied CHO concentrations, doses, or types in the effect measurement. The evidence found was sound enough to support the hypothesis that CHO solutions, when ingested during endurance exercise, have ergogenic action and a possible crossover interaction with the subject’s CRF.

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Nutrient Timing

Kerksick¹,

Cole²

2015

Nutritional Supplements in Sports and Exercise

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Nutrient timing is a popular strategy used by athletes, coaches, and researchers to maximize performance and the adaptations resulting from exercise training. Ingestion of key nutrients before, during, and after various forms of exercise has been shown to favorably impact a number of factors that go on to effect health, performance, and recovery. Research in this area is rapidly expanding, and fi ndings are changing on an annual basis. This chapter is broken into sections discussing current recommendations and scientifi c fi ndings concerning the administration of macronutrients, micronutrients, and other non-nutrients before, during, and after both endurance and resistance exercise. Finally, recommendations are put forth regarding when to employ various strategies, as well as whether certain strategies are worthy of consideration. Key points related to protein timing, caffeine timing, meal patterns, and caloric distribution are all covered in this chapter.

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The performance effect of early versus late carbohydrate feedings during prolonged exercise

Cited by 5 publications

References 32 publications

International society of sports nutrition position stand: nutrient timing

International society of sports nutrition position stand: nutrient timing

Meta-Analysis of Carbohydrate Solution Intake during Prolonged Exercise in Adults: From the Last 45+ Years’ Perspective

Nutrient Timing

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