ImFINE Research Group, Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences-INEF, Universidad Politécnica de Madrid, Madrid, Spain.
Red Española de Investigación en Ejercicio Físico y Salud (EXERNET), Madrid, Spain.
Crit Rev Food Sci Nutr. 2024;64(10):2941-2959. doi: 10.1080/10408398.2022.2128298. Epub 2022 Sep 30.
Carbohydrates (CHO) and caffeine (CAF) are two ergogenic aids commonly used among athletes to enhance performance. However, there is some controversy as to whether the concurrent intake of both supplements might result in an additive and synergistic improvement in exercise performance. The aim of this systematic review and meta-analysis was to determine the effect of adding CAF to a protocol of CHO ingestion, compared with the intake of each ergogenic aid alone and with placebo, on exercise performance and metabolic responses in healthy young physically active adults. This study was conducted according to PRISMA 2020 guidelines. The PubMed, Web of Science, Medline Complete, CINAHL, SPORTDiscus and CENTRAL databases were searched including randomized controlled trials (RCT) that were at least single blind. The risk of bias assessment was performed using the Cochrane Risk-of-Bias tool 2. Meta-analysis were performed on performance variables and rating of perceived exertion (RPE) using the random-effects model. Thirteen RCT with 128 participants (117 men and 11 women) were included in this study. The ingestion of CAF and CHO reduced sprint time during repeated sprint protocols in comparison with CHO isolated ingestion (SMD: -0.45; 95% CI: -0.85, -0.05) while there was a tendency for a reduction in the time employed during time trials (SMD: -0.36; 95% CI: -0.77, 0.05). The RPE tended to be lower with CAF and CHO compared with CHO isolated ingestion during steady-state exercise (SMD: -0.43; 95% CI: -0.91, 0.05) with no differences between conditions in performance trials (SMD: -0.05, 95% CI: -0.39, 0.29). Although most of the studies showed higher values of blood glucose when CHO was co-ingested with CAF compared with PLA, only two studies observed higher values with CHO and CAF co-ingestion with respect to the isolated intake of CHO. One study observed greater fat oxidation and lower glycogen use when CAF was added to CHO. In terms of cortisol levels, one study showed an increase in cortisol levels when CAF was co-ingested with CHO compared with PLA. In summary, concurrent CHO and CAF intake may produce an additive ergogenic effect respect of the isolated ingestion of CHO. This additive effect was present when CHO was provided by a 6-9% of CHO solution (maltodextrin/dextrin + fructose) and CAF is administered in a dose of 4-6.5 mg/kg.
碳水化合物（CHO）和咖啡因（CAF）是运动员常用的两种增强表现的运动补剂，以提高运动表现。然而，关于同时摄入这两种补充剂是否会导致运动表现的额外协同改善，仍存在一些争议。本系统评价和荟萃分析的目的是确定与单独摄入每种运动补剂和安慰剂相比，在健康年轻的体力活动成年人中，同时摄入 CAF 对运动表现和代谢反应的影响。本研究按照 PRISMA 2020 指南进行。检索了 PubMed、Web of Science、Medline Complete、CINAHL、SPORTDiscus 和 CENTRAL 数据库，包括至少为单盲的随机对照试验（RCT）。使用 Cochrane 风险偏倚工具 2 对偏倚风险进行评估。使用随机效应模型对运动表现变量和感知用力评分（RPE）进行荟萃分析。本研究纳入了 13 项 RCT 共 128 名参与者（117 名男性和 11 名女性）。与单独摄入 CHO 相比，CAF 和 CHO 的摄入减少了重复冲刺方案中的冲刺时间（SMD：-0.45；95%CI：-0.85，-0.05），而在计时赛中用时减少的趋势（SMD：-0.36；95%CI：-0.77，0.05）。与单独摄入 CHO 相比，CAF 和 CHO 摄入在稳定状态运动时的 RPE 倾向于降低（SMD：-0.43；95%CI：-0.91，0.05），但在性能试验中无差异（SMD：-0.05，95%CI：-0.39，0.29）。尽管大多数研究表明，CHO 与 CAF 同时摄入时血糖值高于 PLA，但只有两项研究观察到 CHO 与 CAF 同时摄入时血糖值高于 CHO 单独摄入。一项研究观察到，当 CAF 添加到 CHO 中时，脂肪氧化增加，糖原使用减少。关于皮质醇水平，一项研究表明，与 PLA 相比，CHO 与 CAF 同时摄入时皮质醇水平升高。总之，CHO 和 CAF 同时摄入可能会产生相对于 CHO 单独摄入的附加的运动效果。当 CHO 以 6-9%的 CHO 溶液（麦芽糊精/糊精+果糖）提供，CAF 以 4-6.5mg/kg 的剂量给药时，这种附加效应是存在的。
