The Study
Combined glycerol and sodium bicarbonate elicits improvements in fluid retention and blood buffering capacity
This study tested what happens when people drink special mixtures and then measured how their bodies responded—like how much pee they made and how bubbly their blood got. It shows these mixtures do something different than just drinking water, but it didn’t test if they help people run faster or feel better during exercise.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if mixing glycerol (a water-retaining liquid) and sodium bicarbonate (a baking soda-like buffer) helps the body hold onto more water and reduce muscle acidity better than using either alone.
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 561 / 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.
- 1This means athletes might use the mix if they have less time before competition — it works faster than either supplement alone to help with hydration and reduce muscle burn from acid buildup.
- 2The mix kept 64.8% of fluid in the body after 3 hours, better than water (31.6%).
- 3It also raised blood pH by 0.06–0.07 and bicarbonate by 7.1–7.2 mmol/L.
- 4But it didn’t hold more fluid than either supplement alone — just started working sooner.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PLOS One
Year
2026
Authors
B. Patrick, Charles S. Urwin, Andrew C. Betik, William T. Jardine, Rhiannon M. J. Snipe, Monica K. Kelly, D. Hamilton, Amelia J. Carr
Related Content
Claims (6)
In healthy adults, taking sodium bicarbonate at a dose of 0.3 grams per kilogram of body weight, alone or with glycerol, increases blood pH by 0.06–0.07 units and bicarbonate levels by 7.1–7.2 mmol/L 180 minutes after ingestion.
When taken together, glycerol and sodium bicarbonate do not result in higher maximum fluid retention at 180 minutes compared to when either is taken alone in healthy adults, even though fluid retention starts sooner.
Taking sodium bicarbonate alone or with glycerol does not increase plasma volume in healthy adults at rest, even though it improves fluid retention and blood buffering capacity.
Taking glycerol, sodium bicarbonate, or both together does not cause more stomach discomfort in healthy adults than drinking water while at rest.
Taking sodium bicarbonate by mouth reduces acid buildup inside muscle cells during intense exercise, which improves muscle performance.
When healthy adults drink a mixture of 1.0 gram of glycerol and 0.3 gram of sodium bicarbonate per kilogram of body weight, their bodies retain 64.8% of the fluid they consume after 180 minutes, compared to 31.6% when they drink only water. This higher retention begins at 120 minutes and starts earlier than when either substance is taken alone.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.