Sparkling Water vs Still Water: Hydration Comparison
Which is better for staying hydrated?
Quick answer
Sparkling Water vs Still Water: Hydration Comparison
Yes, sparkling water hydrates just as well as still water. In the 2016 Beverage Hydration Index trial (Maughan et al., Am J Clin Nutr; n=72), sparkling water's 4-hour urine output was no different from still water, giving it a hydration index of about 1.0. The carbonation doesn't reduce absorption — it mainly changes comfort, cost, and dental considerations.
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Sparkling water has surged in popularity, but many wonder if those bubbles affect hydration. The good news: sparkling water hydrates just as well as still water. The carbonation doesn't reduce your body's ability to absorb water. However, there are some differences in comfort, cost, and dental considerations worth knowing about.
Key Differences
Carbonation
Sparkling water contains dissolved CO2 that creates bubbles. This can cause bloating in some people but has no impact on hydration efficiency.
Dental Health
Sparkling water is slightly more acidic than still water (pH 3-4 vs 7), but studies show it's far less erosive than soda or juice.
Satiety
The carbonation in sparkling water can make you feel fuller, which may cause some people to drink less overall.
Cost
Sparkling water typically costs 3-5x more than still water, especially when buying pre-bottled brands.
Head-to-Head Comparison
| Feature | Sparkling | Still Water |
|---|---|---|
| Hydration Factor | Excellent | Excellent |
| Calories | 0 (unflavored) | 0 |
| Cost | $1-2 per liter | Nearly free (tap) |
| Convenience | Need to buy or make | Always available |
| Taste | Crisp, bubbly | Clean, neutral |
| Best For | Soda replacement | All-day hydration |
Which Should You Choose?
- If you struggle to drink enough water, sparkling water's taste appeal can help you hit your hydration goals.
- Use sparkling water as a healthy soda replacement — add a squeeze of citrus for extra flavor.
- Stick to still water during intense exercise, as carbonation can cause stomach discomfort.
- Consider a home carbonation machine (like SodaStream) to save money on sparkling water.
- Both count equally toward your daily water intake goal — mix and match as you prefer.
Medical Disclaimer: This comparison is for informational purposes. Individual hydration needs vary.
Sources & Citations
- BHI ≈ 1.0 (no significant difference vs water) — Sparkling water's cumulative 4-hour urine output was not different from still water, giving a beverage hydration index of about 1.0.[1]
- water = 1.00 (reference) — The Beverage Hydration Index anchors still water at 1.00; a value of ~1.0 means a drink is retained as well as plain water.[1]
- n=72; 1 L; 0 beverages below water — In the 72-subject trial, no beverage tested had a hydration index significantly below water, so none caused net dehydration at the 1 L dose.[1]
- 0 beverages below water (n.s.) — No beverage tested had a hydration index significantly lower than water.[2]
- [1]Maughan et al. 2016 (Beverage Hydration Index) — Maughan RJ, Watson P, Cordery PA, Walsh NP, Oliver SJ, Dolci A, Rodriguez-Sanchez N, Galloway SD. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index. Am J Clin Nutr. 2016 Mar;103(3):717-23.PMID: 26702122DOI: 10.3945/ajcn.115.114769
- [2]ACE ProSource (Hydration Index summary) — American Council on Exercise (ACE) ProSource, April 2016. The Newest Index on the Block: The Hydration Index (summary of Maughan et al. 2016).
Last reviewed: 2026-06-21. Every figure on this page is sourced to the named primary references above.
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Frequently Asked Questions
Does sparkling water count toward daily water intake?
Absolutely. Sparkling water hydrates identically to still water and counts fully toward your daily intake goals.
Is sparkling water bad for your teeth?
Plain sparkling water is mildly acidic but far less harmful than soda, juice, or flavored sparkling waters with citric acid. It's generally safe for dental health.
Can sparkling water cause bloating?
The carbonation can cause temporary bloating or gas in some people. If this bothers you, try drinking it slowly or switching to still water.
Is sparkling water bad for your bones?
No. Research shows no link between sparkling water and bone density loss. This myth likely stems from studies on cola (which contains phosphoric acid).
Can I track sparkling water in Vari?
Yes! Vari lets you log sparkling water separately and it counts fully toward your daily hydration goal.
You don’t need to track water manually.
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