Energy Drinks, Pre-Workout and Your Heart: What a New Study Flags

Your pre-workout scoop may deserve a second look. Research to be presented at the American Heart Association's Scientific Sessions 2026, held 6–9 November in Chicago, found that caffeine and stimulant products appear far more often in reports of serious heart events than other foods and supplements, the AHA announced on 2 November.

What the researchers looked at

The team analysed an FDA adverse-event database covering 2017 to 2025. Of 28,345 reports involving people aged 13 and older, 854 concerned energy drinks or stimulant supplements, pre-workout powders included; the rest involved products such as soft drinks, protein bars, shakes and vitamins. Compared with those, caffeine and stimulant products were linked to:

• About 11 times more reports of cardiac arrest.
• About 4.5 times more reports of heart attack.
• About 4 times more reports of ventricular arrhythmias or palpitations.
• Nearly 3 times more reports of a racing heart, and about twice as many reports of fainting.

Who showed up, and the big caveat

About 45% of the cardiovascular reports involved adults aged 18 to 34, and the pattern was similar in men and women. But this is a conference abstract, not yet peer-reviewed, and the reports were submitted voluntarily, so nobody knows how many people used these products without any problem. "For many healthy people, if these products are consumed occasionally, the risk is probably small," said Sai Samayamanthula, a medical student at the University of Virginia School of Medicine, quoted by the AHA. Gregory Marcus of UCSF, who chaired the AHA's 2026 statement on caffeine and was not involved, stressed that "the study does not prove that caffeine products cause these events."

The dose is in the scoop: a product sold as a daily pick-me-up can quietly take you past a full day's caffeine.

A practical caffeine check

• Know the ceiling: the AHA's 2026 scientific statement says up to 400 mg of caffeine a day is generally safe for most adults, about five 8-ounce cups of black coffee.
• Read the label: some energy drinks carry up to three times more caffeine per fluid ounce than brewed coffee.
• Count every source: coffee, energy drinks and supplements add up across the day.
• Scan for other stimulants: the study grouped synephrine, yohimbine, guarana and green tea or coffee extracts with caffeine.
• Don't mix them with alcohol or other drugs; the researchers list mixing among the possible explanations.

Palpitations, chest pain or fainting are reasons to stop and seek medical care, and to tell the doctor exactly what you took. If you have a heart condition, take medication or use these products every day, talk to your doctor about what is safe for you. This article is educational, not medical advice.