A popular workout supplement commonly promoted for athletic performance may actually hinder some of the heart’s beneficial responses to exercise, according to new research from Dalhousie University published in Scientific Reports. The study, which examined sodium nitrate supplementation alongside running in mice, found that while these supplements are often marketed as enhancing cardiovascular health and performance, they can sometimes have unintended negative effects.

While sodium nitrate is commonly found in beetroot-based endurance products designed for runners, cyclists, and fitness enthusiasts, the research suggests that combining it with exercise may prevent several beneficial cardiac improvements typically associated with physical activity. These benefits include changes linked to heart structure, ventricular function, and calcium handling within heart cells, which are crucial for regulating contraction and relaxation.

The study's findings highlight important sex differences in how these supplements affect different genders. The researchers the effects were much less pronounced in male mice compared to females, indicating significant disparities that have often been overlooked in supplement research.

Dr. Susan Howlett, the corresponding author of the study, expressed disappointment with their initial expectations: "We expected nitrates and exercise to work together to improve heart health. Instead, in females, the supplement prevented many of the positive cardiac adaptations normally produced by exercise."

The researchers caution that while these results are promising for understanding potential risks associated with long-term nitrate supplementation, more research is needed to confirm whether similar effects occur in humans. They also emphasize the need for direct studies involving female subjects rather than relying on assumptions based on male participants.

"This study raises important questions about the cardiovascular effects of long-term nitrate supplementation," said Dr. Howlett. "Especially among people using these products alongside regular aerobic exercise, it's crucial to consider how supplements might interact with physical activity."

The findings challenge the assumption that all supplements commonly linked to athletic performance are automatically beneficial and highlight the importance of conducting sex-specific research when studying supplement effects on health.

Publication details: Elise S. Bisset et al., "Sodium nitrate supplementation prevents beneficial cardiac adaptations to running in female mice with few effects on male hearts," Scientific Reports (2026). DOI: 10.1038/s41598-026-50082-4

Key medical concepts: House Mice Clinical categories: Cardiology, Fitness & Physical Activity, Sports Medicine, Women's Health Healthy Living

Who's behind this story? Sadie Harley BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Robert Egan Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language.

Citation: Popular workout supplement may blunt heart benefits of exercise in women (2026, May 15). Retrieved from https://medicalxpress.com/news/2026-05-popular-workout-supplement-blunt-heart.html

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