The Study
Caffeine increases parasympathetic reactivation without altering resting and exercise cardiac parasympathetic modulation: A balanced placebo design
This study found that after exercise, people who drank caffeine had a slight change in their heart rate recovery compared to when they didn’t — but we don’t know if the caffeine actually caused it, because we don’t know how the study was set up. It’s like noticing your friend feels better after eating candy — but maybe they just felt better because they rested.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave young men a small amount of caffeine or a fake pill, and some thought they got caffeine even when they didn't. They measured how fast their heart slowed down after exercise.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 533 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — caffeine helps the heart recover faster after exercise, even if you don’t know you took it.
- 2After exercise, heart recovery was faster with real caffeine (p < 0.05), but not with fake caffeine or when people thought they had caffeine.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Sport Science
Year
2018
Authors
Paloma da Silva Rolim, Raquel Adjafre da Costa Matos, E. D. M. K. Von Koenig Soares, G. E. Molina, C. J. D. da Cruz
Related Content
Claims (4)
High levels of caffeine maintain continuous activity in the body's fight-or-flight system and reduce activity in the rest-and-digest system.
Consuming a small amount of caffeine does not change the activity of the nervous system that slows the heart at rest, whether a person is lying down, standing, or exercising at a moderate intensity.
Believing you consumed caffeine does not change how quickly your heart rate slows down after exercise in young men, based on heart rate variability measurements.
In young, physically active men, consuming approximately 3 mg of caffeine per kilogram of body weight increases the rate at which heart rate slows down after exercise, as measured by the SD1 index of heart rate variability, without changing heart rate variability at rest or during exercise.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.