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A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials.

Pöchmüller M, Schwingshackl L, Colombani PC, Hoffmann G - J Int Soc Sports Nutr (2016)

Bottom Line: Carbohydrate supplements are widely used by athletes as an ergogenic aid before and during sports events.Random effects and fixed effect meta-analyses were performed using the Software package by the Cochrane Collaboration Review Manager 5.3.For those, we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstraße 14 (UZAII), A-1090 Vienna, Austria.

ABSTRACT

Background: Carbohydrate supplements are widely used by athletes as an ergogenic aid before and during sports events. The present systematic review and meta-analysis aimed at synthesizing all available data from randomized controlled trials performed under real-life conditions.

Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched systematically up to February 2015. Study groups were categorized according to test mode and type of performance measurement. Subgroup analyses were done with reference to exercise duration and range of carbohydrate concentration. Random effects and fixed effect meta-analyses were performed using the Software package by the Cochrane Collaboration Review Manager 5.3.

Results: Twenty-four randomized controlled trials met the objectives and were included in the present systematic review, 16 of which provided data for meta-analyses. Carbohydrate supplementations were associated with a significantly shorter exercise time in groups performing submaximal exercise followed by a time trial [mean difference -0.9 min (95 % confidence interval -1.7, -0.2), p = 0.02] as compared to controls. Subgroup analysis showed that improvements were specific for studies administering a concentration of carbohydrates between 6 and 8 % [mean difference -1.0 min (95 % confidence interval -1.9, -0.0), p = 0.04]. Concerning groups with submaximal exercise followed by a time trial measuring power accomplished within a fixed time or distance, mean power output was significantly higher following carbohydrate load (mean difference 20.2 W (95 % confidence interval 9.0, 31.5), p = 0.0004]. Likewise, mean power output was significantly increased following carbohydrate intervention in groups with time trial measuring power within a fixed time or distance (mean difference 8.1 W (95 % confidence interval 0.5, 15.7) p = 0.04].

Conclusion: Due to the limitations of this systematic review, results can only be applied to a subset of athletes (trained male cyclists). For those, we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min.

No MeSH data available.


Related in: MedlinePlus

Effects of carbohydrate interventions as compared to placebo on mean power output. Forest plot shows pooled mean differences with 95 % confidence intervals (CI) for 4 randomized controlled trials. Subgroup analyses show the results for exercise duration shorter than 90 min or longer than 90 min, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses
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Fig5: Effects of carbohydrate interventions as compared to placebo on mean power output. Forest plot shows pooled mean differences with 95 % confidence intervals (CI) for 4 randomized controlled trials. Subgroup analyses show the results for exercise duration shorter than 90 min or longer than 90 min, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses

Mentions: For each of the four groups, results of both comprehensive as well as subgroup meta-analyses are given in Figs. 2, 3, 4 and 5, respectively. Please note that classification into subgroups was performed for every group independent of resulting numbers of studies.Fig. 2


A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials.

Pöchmüller M, Schwingshackl L, Colombani PC, Hoffmann G - J Int Soc Sports Nutr (2016)

Effects of carbohydrate interventions as compared to placebo on mean power output. Forest plot shows pooled mean differences with 95 % confidence intervals (CI) for 4 randomized controlled trials. Subgroup analyses show the results for exercise duration shorter than 90 min or longer than 90 min, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4940907&req=5

Fig5: Effects of carbohydrate interventions as compared to placebo on mean power output. Forest plot shows pooled mean differences with 95 % confidence intervals (CI) for 4 randomized controlled trials. Subgroup analyses show the results for exercise duration shorter than 90 min or longer than 90 min, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses
Mentions: For each of the four groups, results of both comprehensive as well as subgroup meta-analyses are given in Figs. 2, 3, 4 and 5, respectively. Please note that classification into subgroups was performed for every group independent of resulting numbers of studies.Fig. 2

Bottom Line: Carbohydrate supplements are widely used by athletes as an ergogenic aid before and during sports events.Random effects and fixed effect meta-analyses were performed using the Software package by the Cochrane Collaboration Review Manager 5.3.For those, we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstraße 14 (UZAII), A-1090 Vienna, Austria.

ABSTRACT

Background: Carbohydrate supplements are widely used by athletes as an ergogenic aid before and during sports events. The present systematic review and meta-analysis aimed at synthesizing all available data from randomized controlled trials performed under real-life conditions.

Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched systematically up to February 2015. Study groups were categorized according to test mode and type of performance measurement. Subgroup analyses were done with reference to exercise duration and range of carbohydrate concentration. Random effects and fixed effect meta-analyses were performed using the Software package by the Cochrane Collaboration Review Manager 5.3.

Results: Twenty-four randomized controlled trials met the objectives and were included in the present systematic review, 16 of which provided data for meta-analyses. Carbohydrate supplementations were associated with a significantly shorter exercise time in groups performing submaximal exercise followed by a time trial [mean difference -0.9 min (95 % confidence interval -1.7, -0.2), p = 0.02] as compared to controls. Subgroup analysis showed that improvements were specific for studies administering a concentration of carbohydrates between 6 and 8 % [mean difference -1.0 min (95 % confidence interval -1.9, -0.0), p = 0.04]. Concerning groups with submaximal exercise followed by a time trial measuring power accomplished within a fixed time or distance, mean power output was significantly higher following carbohydrate load (mean difference 20.2 W (95 % confidence interval 9.0, 31.5), p = 0.0004]. Likewise, mean power output was significantly increased following carbohydrate intervention in groups with time trial measuring power within a fixed time or distance (mean difference 8.1 W (95 % confidence interval 0.5, 15.7) p = 0.04].

Conclusion: Due to the limitations of this systematic review, results can only be applied to a subset of athletes (trained male cyclists). For those, we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min.

No MeSH data available.


Related in: MedlinePlus