The Study
Carbohydrate hastens hypervolemia achieved through ingestion of aqueous sodium solution in resting euhydrated humans
This study shows that when young men drink a salty drink with a type of sugar called dextrin, their blood volume goes up faster than with just salty water. It doesn’t prove the dextrin caused it for sure, but it suggests there might be a link.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When boys drink salt water, their blood gets more fluid after 60 minutes. If they drink salt water with a type of sugar (dextrin), it fills up by 30 minutes. Water alone doesn’t add extra blood fluid because the body pees it out.
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 537 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The body holds onto salt and sugar drinks better and faster, which could help in recovery or hydration situations.
- 2Salt drinks: +211–329 mL fluid in body, less pee.
- 3Salt + sugar drink: blood volume up in 30 min (vs 60 min for salt alone).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Applied Physiology
Year
2021
Authors
Naoto Fujii, Akira Sugihara, Kazuhito Watanabe, Takehiro Niwa, Akira Katagiri, Shodai Moriyama, Izumi Miyanagi, Jumpei Kojima, T. Nishiyasu
Related Content
Claims (4)
Eating a lot of carbs might make your body hold onto more salt, which could raise your blood pressure.
Drinking salt water (with a little salt) can boost blood volume in healthy young guys at rest, and the effect starts within an hour and lasts. Plain water doesn’t do this because it makes you pee more and dilutes your blood.
Drinking a sports-type drink with carbs and salt boosts blood volume faster than drinking salt water alone — it starts working in 30 minutes instead of 60, at least in healthy young guys just sitting around.
If young, healthy guys at rest drink salty water (with 0.7% or 0.9% salt), they hold onto more fluid than if they drank plain water—because they pee less and their body fluids stay balanced.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.