Does a sports drink hold water in better than plain water?
The full question we checked: Does a sports drink help you 'hold' water better than plain water?
rehydration
About the same — an ordinary sports drink ties water; only sweeter or saltier drinks hold more.
Four randomized trials, split at the margin: two find a tie, two find a small edge — reconciled by a dose threshold for sugar and sodium.
Weight of evidence
Point to “no”
2studies
Nuance / against
2studies
Added context
1studies
Confidence
Moderate
Papers held
5quote-checked
In short
- A standard sports drink (~6% sugar, ~20 mmol/L sodium) sits right at the dose where retention starts to rise, so trials split on whether it beats water.
- What clearly holds water better is more sugar or more salt: above ~10% sugar or ~27 mmol/L sodium — oral rehydration salts and milk.
- 'Holding water' only matters when you cannot refill; if water is within reach, the difference either way is small.
When it might be different
Two things shift the answer. Dose: push sugar above ~10% or sodium above ~27 mmol/L (proper oral rehydration salts, milk) and a drink is held clearly better — an ordinary sports drink sits just under that line. Hydration state: right after a heavy sweat, when you start dehydrated, sodium in the drink does improve how much you keep. And if you genuinely cannot refill — rationing fluid in the field — holding more of each sip matters. Those are separate questions from everyday sipping.
What to do
For everyday sipping where you can refill, plain water does the job about as well as an ordinary sports drink, for less money. If you specifically want the most retention when fluid is scarce, reach for oral rehydration salts or milk — their higher sodium and sugar are what actually hold water. Otherwise drink a sports drink because you like the taste.
The evidence — all 5 studies
The verdict rests on
The other side — kept in view
Every study below leads with plain English; its exact quoted words sit one tap away. “The other side” is shown on purpose — it’s how you can trust the rest.
The trials that found a tie 2
Controlled trials: people drank a measured litre of each drink, then all their urine was collected for hours to see how much they actually kept.
72 adults each drank a litre of several drinks; a sports drink was retained no better than plain water, while oral rehydration salts and milk were kept significantly better.
Their exact words · our check
“were not different from the response to water ingestion”
“The mean BHI at 2 h was 1.54 ± 0.74 for the ORS, 1.50 ± 0.58 for full-fat milk, and 1.58 ± 0.60 for skimmed milk”
Am J Clin Nutr 103(3):717-723 · DOI 10.3945/ajcn.115.114769 · full text read & held
Repeated in 40 adults including women: same result — a sports drink tied plain water on the retention score, with no difference between men and women.
Their exact words · our check
“water (1.0 ± 0.0), AA-ORS (1.15 ± 0.28), G-ORS (1.21 ± 0.28), and SpD (1.09 ± 0.26). The BHI for both AA-ORS and G-ORS was greater than that for water (P < 0.05)”
“neither body mass nor sex independently affected BHI”
Am J Clin Nutr 107(4):544-549 · DOI 10.1093/ajcn/nqy005 · abstract only — paywalled
Why the dose decides 1
The same group varied one ingredient at a time to find what actually moves retention.
Varied one ingredient at a time across three groups of 12 men: retention rose only above ~10% sugar or ~27 mmol/L sodium, and caffeine up to 400 mg/L did nothing. An ordinary sports drink (~6% sugar, ~20 mmol/L sodium) sits just below both thresholds.
Their exact words · our check
“after 27 and 52 mmol/L sodium beverages than 7 and 15 mmol/L sodium beverages (p < .05)”
“after 10 and 20% sucrose beverages than 0 and 5% sucrose beverages”
“No difference in urine output or net fluid balance was apparent following ingestion of caffeine at concentrations of 0-400 mg/L”
Int J Sport Nutr Exerc Metab 29(1):51-60 · DOI 10.1123/ijsnem.2018-0047 · abstract only — full text not retrievable
Where a sports-type drink did edge water 2
Two trials where a Gatorade-type or carbohydrate-electrolyte drink was held better than water — kept in view on purpose.
24 adults, young and older, both sexes, drank water or one of four sodium beverages including G-20 (Gatorade). Every beverage, the Gatorade included, was retained significantly better than water.
Their exact words · our check
“BHI was significantly greater than 1.0 for all test beverages at both 2 and 4 h postconsumption”
“AA-60 = 1.24 ± 0.10 compared with water = 1.00, P = 0.01”
Am J Clin Nutr 109(6):1640-1647 · DOI 10.1093/ajcn/nqz009 · free full text · full text read & held
19 adults drank water, electrolytes-only, carbohydrate-electrolytes, or a dipeptide drink. The carbohydrate-electrolyte drink (sports-drink-like) was retained better than water — but electrolytes alone at sports-drink levels were not.
Their exact words · our check
“Compared to W, BHI was higher (p = 0.007) for C + E (1.15 ± 0.17) after 120 min”
“the BHI of sports drinks (~20 mmol sodium) does not necessarily yield a significantly greater BHI compared to the water control”
Nutrients 13(9):2933 · DOI 10.3390/nu13092933 · free full text · full text read & held
Where this applies, and how sure we are
Applies to
Does not cover
- dehydrated / post-exercise rehydration (where sodium DOES help — see related claim)
- performance or thermoregulation during exercise
- children
How confident we are
Moderate confidence. Four randomized crossover trials in euhydrated adults, split at the margin: Maughan 2016 and Sollanek 2018 find an ordinary sports drink ties water, while Clarke 2019 (every sodium beverage incl. a Gatorade-type beat water) and Millard-Stafford 2021 (carbohydrate-electrolyte beat water) find a small edge. Maughan 2019's dose-response — retention rises only above ~10% sucrose or ~27 mmol/L sodium — reconciles the split: a standard sports drink sits at the threshold, so studies land on either side. No systematic review or meta-analysis of the BHI exists (PubMed, checked 2026-08-25), so this is a narrative synthesis of the primary trials, not a pooled estimate.
How we read the science
How far we read each paper. When a paper is free to read, we fetch the full text, read it, hold a copy and fingerprint it — flagged full text read & held. When it is paywalled we can only quote the public abstract — flagged abstract only — paywalled. Either way the quoted words are copied verbatim from the copy we hold, so they cannot drift.
We keep the papers that disagree. Where a study cuts against our answer, we show it in full rather than hide it — that’s how you can trust the ones that agree.
Claim id sports-drink-no-better-than-water-for-retention-when-euhydrated · built from evidence/claims.yaml + sources.yaml · 25 Aug 2026.