Wake Up and Smell the Coffee
A comprehensive look at caffeine supplementation and exercise performance.
The study "Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses" published in the British Journal of Sports Medicine provides a comprehensive analysis of the impact of caffeine on exercise performance by reviewing existing meta-analyses.
Key Points
Objective: To systematically review and appraise findings from published meta-analyses regarding the effects of caffeine on exercise performance.
Design: An umbrella review encompassing multiple systematic reviews and meta-analyses.
Findings: Caffeine ingestion is generally ergogenic across various exercise domains, notably aerobic endurance, muscle strength, muscle endurance, power, jumping performance, and speed.
Aim
The study aimed to:
Systematically review available meta-analytical evidence on caffeine's effects on exercise performance.
Assess the quality, strengths, and limitations of the meta-analytical evidence.
Identify gaps in the literature and suggest areas for future research.
Methods
Data Sources: The authors conducted a systematic search across 12 databases (including PubMed, Cochrane Library, and Scopus) until September 2018.
Eligibility Criteria: Included meta-analyses that examined acute caffeine effects on exercise performance outcomes. Studies that combined caffeine with other ergogenic compounds were excluded unless caffeine's effects could be isolated.
Data Extraction: Information such as authorship, number of studies included, pooled effect sizes, and confidence intervals were extracted.
Quality Assessment: The methodological quality of the included meta-analyses was evaluated using the AMSTAR 2 checklist, while the quality of evidence was assessed using GRADE principles.
Results
Included Studies: Out of 405 initial records, 11 reviews containing 21 meta-analyses were included. All reviews had moderate to high methodological quality.
Performance Enhancements: Caffeine was found to enhance performance in:
Aerobic endurance
Muscle strength
Muscle endurance
Anaerobic power
Speed and jumping performance
Quality of Evidence: Most evidence was categorised as moderate quality; however, some outcomes had low to very low-quality evidence. The effect of caffeine was generally more significant for aerobic compared to anaerobic exercises.
Related
Key Takeaways
Caffeine ingestion benefits a wide range of physical activities, particularly in enhancing aerobic endurance and muscle performance.
The review highlights a need for further research focusing on diverse populations (e.g., women and older adults) to enhance the generalizability of findings.
The findings suggest that while caffeine is an effective ergogenic aid, individual responses may vary, necessitating personalised approaches for athletic performance.
This umbrella review is a valuable resource for athletes, coaches, and sports nutritionists. It consolidates current knowledge on caffeine's ergogenic effects and guides future research directions.
Reference
Grgic J, Grgic I, Pickering C, et al. Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses. British Journal of Sports Medicine 2020;54:681-688.