Synergy of carbohydrate and caffeine ingestion on physical performance and metabolic responses to exercise: A systematic review with meta-analysis

Thirteen randomized controlled trials with 128 participants indicate that the ingestion of caffeine and carbohydrates together may reduce sprint time compared to carbohydrates alone.

• Combining caffeine and carbohydrates reduced sprint time during repeated sprint protocols (SMD: -0.45; 95% CI: -0.85, -0.05).
• There was a tendency for reduced time in time trials with combined caffeine and carbohydrates, but results were less conclusive (SMD: -0.36; 95% CI: -0.77, 0.05).
• Rating of perceived exertion (RPE) was lower with combined caffeine and carbohydrates compared to carbohydrates alone during steady-state exercise (SMD: -0.43; 95% CI: -0.91, 0.05).
• Higher blood glucose levels were observed when carbohydrates were co-ingested with caffeine compared to placebo, though findings were inconsistent across studies.
• One study indicated greater fat oxidation and lower glycogen use when caffeine was added to carbohydrates.
• Increased cortisol levels were noted with the co-ingestion of caffeine and carbohydrates compared to placebo in one study.

AI simplified